Journal articles: 'Multilayers'

1

Park, Geun Woo, and Hyuck Sang Kwon. "Structural and Mechanical Properties of Multilayered CVD TiC/TiCN Coatings with Variations of Multilayer Period." Materials Science Forum 534-536 (January 2007): 1233–36. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.1233.

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Multilayered coatings on tungsten carbide cutting tools are widely used for enhancing cutting performance. In this paper, we review the CVD TiC/TiCN multilayer as a function of the multilayer period. The TiC/TiCN multilayers in initial stage show preferred (220) orientation but shifts to (200) orientation with decreasing multilayer period. The nanohardness of TiC/TiCN multilayers were found to increase with decreasing multilayer period and shows a maximum of 23.8 GPa at a period = 33.5 nm.

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Kaneko, Yoshihisa, H. Sakakibara, and Satoshi Hashimoto. "Dependence of Vickers Hardness on Annealing Temperature at Co/Cu Multilayered Films." Materials Science Forum 561-565 (October 2007): 2399–402. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.2399.

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Co/Cu and Ni/Cu multilayers fabricated by electroplating technique were annealed at various temperatures in order to investigate thermal stability of multilayered structures. Vickers hardness tests on the annealed Co/Cu and Ni/Cu multilayers were conducted at room temperature. It was recognized that after the annealing at 1023K the Co/Cu multilayer still maintained the hardness of as-deposited state. On the other hand, the hardness of Ni/Cu multilayer was almost identical to copper substrate after the annealing at 903K.

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Kaneko, Yoshihisa, T. Sanda, and Satoshi Hashimoto. "Microstructures of Ni/Cu and Ni-Co/Cu Multilayers Produced by Electrodeposition Method." Advanced Materials Research 26-28 (October 2007): 1321–24. http://dx.doi.org/10.4028/www.scientific.net/amr.26-28.1321.

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Microstructures of Ni/Cu and Ni-Co/Cu multilayers were investigated by X-ray diffraction analysis. These multilayered structures were fabricated on copper substrates using electrodeposition technique. At an as-deposited Ni/Cu multilayer with the layer thickness of h=5nm, a single diffraction peak appeared, although the multilayer of h=100nm exhibited the diffractions splitting into two peaks which resulted from both the Ni and Cu layers. In the Ni-Co/Cu multilayers, it was found that composition of the Ni-Co layer depended on an electric potential applied during deposition. The fcc and hcp structures were detected at the Ni-rich and the Co-rich deposits, respectively. The Vickers hardness of the Co-Ni/Cu multilayer was higher than that of the Ni/Cu multilayer.

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Sattler, Margaret L., and Michael A. O'Keefe. "HRTEM simulation of interfacial structure in amorphous multilayers." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 466–67. http://dx.doi.org/10.1017/s0424820100154305.

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Multilayered materials have been fabricated with such high perfection that individual layers having two atoms deep are possible. Characterization of the interfaces between these multilayers is achieved by high resolution electron microscopy and Figure 1a shows the cross-section of one type of multilayer. The production of such an image with atomically smooth interfaces depends upon certain factors which are not always reliable. For example, diffusion at the interface may produce complex interlayers which are important to the properties of the multilayers but which are difficult to observe. Similarly, anomalous conditions of imaging or of fabrication may occur which produce images having similar traits as the diffusion case above, e.g., imaging on a tilted/bent multilayer sample (Figure 1b) or deposition upon an unaligned substrate (Figure 1c). It is the purpose of this study to simulate the image of the perfect multilayer interface and to compare with simulated images having these anomalies.

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TAN, M., D. J. LI, G. Q. LIU, L. DONG, X. Y. DENG, H. LIU, and X. SUN. "STRUCTURES AND MECHANICAL PROPERTIES OF MODULATED ZrB2/W AND ZrB2/WNx NANOMULTILAYERS." International Journal of Modern Physics B 24, no. 01n02 (January 20, 2010): 34–42. http://dx.doi.org/10.1142/s0217979210063958.

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ZrB 2, W , WN x coatings and ZrB 2/ W , ZrB 2/ WN x multilayered coatings have been synthesized by ion beam assisted deposition at room temperature. X-ray diffraction (XRD), XP-2 surface profiler, scanning electron microscopy (SEM) and nano indenter were employed to investigate the influence of modulation periods and N + beam bombardment on microstructure and mechanical properties of the coatings. The low-angle XRD patterns and cross-sectional SEM indicate a well-defined composition modulation and layer structure of the multilayers. The multilayers with modulation periods ranging from 9 to 16 nm without N + bombardment possessed higher hardness and elastic modulus than the rule-of-mixtures value of monolithic ZrB 2 and W coatings. The highest hardness was 24 GPa. N + bombardment to growing multilayers gave a significant contribution to mechanical property enhancement. When modulation period is 9.6 nm, ZrB 2/ WN x multilayer with 200 eV N + bombardment reveals the highest hardness (30.2 GPa) and elastic modulus. This hardest multilayer also showed the improved residual stress and fracture resistance.

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Li, Y. P., G. P. Zhang, and Z. G. Wang. "Strength and Plastic Deformation Behavior of Nano-Scale Au/Cu and Cr/Cu Multilayers." Advanced Materials Research 41-42 (April 2008): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.41-42.3.

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Nano-scale Au/Cu multilayers were investigated by nano/microindentation. It was found that the hardness of the multilayers increases with decreasing individual layer thickness (λ), and shear band deformation can occur more easily in the multilayer with small λ. For comparison, the same experiments were also performed on Cr/Cu multilayers with the same layer structure. The results show that the Cr/Cu multilayer can be more effective in resisting shear band deformation than the Au/Cu multilayer. Finally, the λ dependence of shear band deformation and the difference between plastic deformation behaviors of the two multilayers were analyzed based on dislocation plasticity.

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7

Yue, Jian Ling, Wei Shi, and Ge Yang Li. "Modulation Structure and Superhardness Effect of VC/TiN Nano-Multilayer Films." Applied Mechanics and Materials 184-185 (June 2012): 1080–83. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.1080.

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A series of VC/TiN nano-multilayer films with various TiN layer thicknesses were synthesized by magnetron sputtering method. The relationship between the modulation structure and superhardness effect of the multilayer films were investigated. The results reveal that TiN below a critical layer thickness grows coherently with VC layers in multilayers. Correspondingly, the hardness and elastic modulus of the multilayers increase significantly. The maximum hardness and modulus achieved in these multilayers is 40.7GPa and 328GPa.With further increase in the TiN layer thickness, coherent structure of multilayers are destroyed, resulting in a remarkable decrease of hardness and modulus. The superhardness effect of multilayers is related to the three directional strains generated from the coherent structure.

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8

Poulopoulos, Panagiotis, S. D. Pappas, Vassilios Kapaklis, P. E. Jönsson, E. T. Papaioannou, A. Delimitis, D. Trachylis, M. J. Velgakis, Efstathios I. Meletis, and C. Politis. "Growth and Magnetism of Natural Multilayers." Journal of Nano Research 15 (September 2011): 95–103. http://dx.doi.org/10.4028/www.scientific.net/jnanor.15.95.

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. In this work, we present a simple method to fabricate high quality Ni/NiO multilayers with the use of a single magnetron sputtering head. Namely, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer (~ 1nm) is formed by natural oxidation. The process is reproducible and the result is the formation of a multilayer with excellent layering. Magnetization hysteresis loops recorded at 5 K and room temperature reveal a tendency for perpendicular magnetic anisotropy as the thickness of the individual Ni layers decreases. It is shown that the Ni/NiO interface has sizeable positive surface/interface anisotropy, i.e. it favors the development of perpendicular magnetic anisotropy. This is rather unusual for a Ni-based multilayered system and may render Ni/NiO multilayers useful for magneto-optical recording applications.

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9

Buznikov, Nikita A., and Galina V. Kurlyandskaya. "Magnetoimpedance in Symmetric and Non-Symmetric Nanostructured Multilayers: A Theoretical Study." Sensors 19, no. 8 (April 12, 2019): 1761. http://dx.doi.org/10.3390/s19081761.

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Intensive studies of the magnetoimpedance (MI) effect in nanostructured multilayers provide a good phenomenological basis and theoretical description for the symmetric case when top and bottom layers of ferromagnet/conductor/ferromagnet structure have the same thickness and consist of one magnetic layer each. At the same time, there is no model to describe the MI response in multilayered films. Here, we propose the corresponding model and analyze the influence of the multilayer parameters on the field and frequency dependences of the MI. The approach is based on the calculation of the field distribution within the multilayer by means of a solution of lineralizied Maxwell equations together with the Landau–Lifshitz equation for the magnetization motion. The theoretical model developed allows one to explain qualitatively the main features of the MI effect in multilayers and could be useful for optimization of the film parameters. It might also be useful as a model case for the development of MI magnetic biosensors for magnetic biomarker detection.

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10

Kusi-Appiah, Aubrey E., Troy W. Lowry, Nicholas Vafai, David H. Van Winkle, and Steven Lenhert. "Fluid Lipid Multilayer Stabilization by Tetraethyl Orthosilicate for Underwater AFM Characterization and Cell Culture Applications." MRS Advances 2, no. 57 (2017): 3553–58. http://dx.doi.org/10.1557/adv.2017.502.

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ABSTRACTStabilization of surface supported fluid lipid multilayers for underwater characterization is an essential step in making them useful for scalable cell culture applications such as high throughput screening. To this end, we used tetraethyl orthosilicate (TEOS), recently shown to stabilize fluid lipid films while maintaining their fluidity and functionality under water, to stabilize lipid multilayer micropatterns of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). The treated multilayers were immersed under water and successfully imaged by atomic force microscopy (AFM), a difficult feat to perform on fluid lipid multilayers without TEOS treatment. The treated lipid multilayer showed an average swelling of approximately 18% in water but remained stable during the imaging process. The TEOS-treated lipid multilayers also proved compatible with cell culture as HeLa, MDCK, and HEK cell types all adhered and grew in high numbers over the multilayers. The results obtained here open the door to the use of fluid lipid multilayers in biotechnology applications such as microarray based high throughput cell assays.

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11

Suzuki, Kosuke, Naoto Go, Shun Emoto, Ryutaro Yamaki, Masayoshi Itou, Yoshiharu Sakurai, and Hiroshi Sakurai. "Observation of Magnetic Compton Profile of Interface Controlled Co/Pd Multilayer." Key Engineering Materials 497 (December 2011): 8–12. http://dx.doi.org/10.4028/www.scientific.net/kem.497.8.

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We compare two Co/Pd multilayers with correspondingly smooth and rough interfaces. The first is a Co (1.5 nm)/Pd (2.6 nm) multilayer with a smooth interface deposited by the MBE technique, and the second is a Co (1.6 nm)/Pd (4.0 nm) multilayer with a rough interface deposited by the sputter technique. Both multilayers have almost the same perpendicular magnetic anisotropy energy, 1.15 Merg/cc for the Co (1.5 nm)/Pd (2.6 nm) multilayer and 1.20 Merg/cc for the Co (1.6 nm)/Pd (4.0 nm) multilayer, respectively. The symmetry of the wave function, which is measured using the magnetic Compton profile, is almost the same for both multilayers. This suggests that the smooth interface controls the wave function and enhances the PMA energy even if the Co/Pd multilayer has a thinner Pd layer.

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12

DONG, L., G. Q. LIU, Y. D. SUN, M. Y. LIU, and D. J. LI. "EFFECT OF DEPOSITION PARAMETERS ON STRUCTURE AND MECHANICAL PROPERTIES OF TiB2/Si3N4 NANO MULTILAYERS." International Journal of Modern Physics B 24, no. 01n02 (January 20, 2010): 43–50. http://dx.doi.org/10.1142/s021797921006396x.

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TiB 2/ Si 3 N 4 nano multilayers have been synthesized under different deposition parameters related to substrate by ion beam assisted deposition (IBAD). XRD, Nano indenter, profiler, and multi-functional tester for material surface properties were used to characterize the microstructure and mechanical properties of the multilayers. The results indicated a well-defined composition modulation and layer structure of the multilayers. To the multilayers with constant modulation ratio of 15.4:1 and modulation period of 11.8 nm, the multilayer deposited on Al 2 O 3(111) substrate with 38 nm-thick Ti buffer layer at deposition temperature of 225°C revealed the highest hardness (37.4 GPa) and elastic modulus. This hardest multilayer also showed the improved residual stress, friction coefficient, and fracture resistance.

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13

Hattori, Tomoya, Yoshihisa Kaneko, and Satoshi Hashimoto. "Tribological Properties of Ni/Cu Multilayers." Materials Science Forum 561-565 (October 2007): 2451–54. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.2451.

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Sliding wear and hardness tests in Ni/Cu multilayers electrodeposited on polycrystalline copper substrate were carried out. The multilayers had a total thickness of 5 μm and an individual layer thickness from 5 to 100 nm. Hardness of the multilayers measured with a nanoindentation tester was found to be dependent on layer thickness. The multilayer with the layer thickness of 20 nm showed the highest value among them. It was found that the wear resistances of all the multilayers tested were higher than that of an electrodeposited nickel coating. It was also revealed that the specific wear rate of multilayers decreased with decreasing the layer thickness although the highest hardness was attained at the 20 nm layer thickness. Scanning ion microscope observation showed that the subsurface area kept the layered structure of nickel and copper even after sliding wear. The multilayer had plasticity sufficient to accommodate deformation coming from the sliding wear, because fine grains peculiar to severe plastic deformation process were formed near the worm surface.

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14

Oyama, Makiko, Hiroaki Ozawa, Takumi Nagashima, Masa-aki Haga, and Takao Ishida. "Effects of Fe cations in ruthenium-complex multilayers fabricated by a layer-by-layer method." Physical Chemistry Chemical Physics 18, no. 13 (2016): 9005–12. http://dx.doi.org/10.1039/c5cp07970e.

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Molecular multilayers were fabricated using a Ru complex containing Fe cations on an indium tin oxide surface to control the properties of the Ru-complex multilayers such as the multilayer orientation and the electron transport.

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15

Mathew, Jissy. "FABRICATION OF NANO-STRUCTURED SURFACES BY FINE TUNING OF DEPOSITION PARAMETERS IN CHITOSAN/PSS POLYELECTROLYTE MULTILAYERS." Journal of Advanced Scientific Research 13, no. 11 (December 31, 2022): 63–68. http://dx.doi.org/10.55218/jasr.2022131110.

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The fabrication of chitosan/polystyrene sulfonate (CHI)/(PSS) polyelectrolyte multilayer on different polymeric supports (polyether sulfone, polycarbonate and nylon), is discussed in the present work. The permeation of model protein BSA through these multilayer membranes was carried out under ultrafiltration conditions. Different multilayer systems were prepared by varying the parameters such as nature of the polymeric support, pH and molecular weight of polyelectrolyte. Build up of multilayers on polymeric support was monitored by measuring area under the sulfonate peak at 1033 cm-1 in the FTIR spectrum. No appreciable rejection of BSA was observed when CHI/PSS multilayers were fabricated on polycarbonate and nylon supports even after 15 bilayer coating. When multilayers were fabricated on polyether sulfone membranes, more than 90% rejection of BSA was observed with 5 bilayer coated membrane. This study reveals that pH and molecular weight of the polyelectrolyte has decisive role in the multilayer build up.

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Chen, J., E. D. Rippert, S. N. Song, M. P. Ulmer, and J. B. Ketterson. "High quality a-Si/Nb and a-SiN/NbN artificial multilayers for Josephson applications." Journal of Materials Research 9, no. 7 (July 1994): 1678–82. http://dx.doi.org/10.1557/jmr.1994.1678.

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A high resolution transmission electron microscopy study of multilayer films prepared by magnetron sputtering shows that the morphology of the growing interface in a-Si/Nb and a-SiN/NbN multilayers is remarkably uniform and smooth; this is in contrast to the polycrystalline AlN/NbN multilayers grown under similar conditions, which exhibit columnar grain structure with rough interfaces. For proper sputtering parameters, the amorphous layers seem to periodically restore a relatively smooth initial interface condition for the successive Nb (or NbN) layer growth, consequently interrupting the tendency toward increased roughness due to mechanisms such as columnar growth. Artificial multilayers having very flat interfaces could stimulate applications based on multilayer Josephson junctions.

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17

Ghafoor, Naureen, Fredrik Eriksson, Arkady S. Mikhaylushkin, Igor A. Abrikosov, Eric M. Gullikson, Ulrich Kressig, Manfred Beckers, Lars Hultman, and Jens Birch. "Effects of O and N impurities on the nanostructural evolution during growth of Cr/Sc multilayers." Journal of Materials Research 24, no. 1 (January 2009): 79–95. http://dx.doi.org/10.1557/jmr.2009.0004.

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Transition metal multilayers are prime candidates for high reflectivity soft x-ray multilayer mirrors. In particular, Cr/Sc multilayers in the amorphous state have proven to give the highest reflectivity in the water window. We have investigated the influence of impurities N and O as residual gas elements on the growth, structure, and optical performance of Cr/Sc multilayers deposited in high vacuum conditions by a dual cathode direct current magnetron sputter deposition. Multilayer structures with the modulation periods in the range of 0.9–4.5 nm and Cr layer to bilayer thickness ratios in the range of 0.17–0.83 were deposited with an intentionally raised base pressure (pB), ranging from 2 × 10−7 to 2 × 10−5 Torr. Compositional depth profiles were obtained by elastic recoil detection analysis and Rutherford backscattering spectroscopy, while the structural investigations of the multilayers were carried out using hard x-ray reflectivity and transmission electron microscopy. By investigating stacked multilayers, i.e., several multilayers with different designs of the modulation periods, stacked on top of each other in the samples, we have been able to conclude that both N and O are incorporated preferentially in the interior of the Sc layers. At pB ≤ 2 × 10−6 Torr, typically <3 at.% of N and <1.5 at.% of O was found, which did not influence the amorphous nanostructure of the layers. Multilayers deposited with a high pB ∼2 × 10−5 Torr, a N content as high as ∼37 at.% was measured by elastic recoil detection analysis. These multilayers mainly consist of understoichiometric face-centered cubic CrNx/ScNy nanocrystalline layers, which could be grown as thin at 0.3 nm and is explained by a stabilizing effect on the ScNy layers during growth. It is also shown that by adding a background pressure of as little as 5 × 10−6 Torr of pure N2 the soft x-ray reflectivity (λ = 3.11 nm) can be enhanced by more than 100% by N incorporation into the multilayer structures, whereas pure O2 at the same background pressure had no effect.

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18

Wang, Yufei, Shuangle Zhang, Zefeng Wu, Yong Fan, Huaqiang Chen, Qingning Meng, Yang Yan, Zhaoyi Hu, Jing Wang, and Engang Fu. "Design and Preparation of Nanoporous Cu/Ag Multilayer Films." Coatings 11, no. 10 (September 29, 2021): 1187. http://dx.doi.org/10.3390/coatings11101187.

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Cu30Al70 and Ag30Al70 multilayer precursor films were prepared by magnetron sputtering, respectively. Then the nanoporous Cu/Ag multilayer composite films were successfully prepared by selecting the appropriate H2SO4 solution as the dealloying solution. It was found that the nanoporous structure was stable in the dealloying solution. The morphology and structure of nanoporous multilayer films are mainly related to the phase composition of precursors. The structure of nanoporous multilayers can be simply regarded as the superposition of single-layer structures. Our work shows that nanoporous multilayers can be well-prepared by magnetron sputtering combined with dealloying.

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19

Yue, Jiang Ling, Yan Sheng Yin, and Ge Yang Li. "Microstructure, Mechanical Properties and Thermal Stability of TiAlN/Si₃N₄ Nano-Multilayer Films Deposited by Reactive Magnetron Sputtering." Advanced Materials Research 79-82 (August 2009): 489–92. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.489.

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A series of TiAlN/Si3N4 nano-multilayer films with various Si3N4 layer thicknesses were prepared by reactive magnetron sputtering. These multilayers were then annealed at temperatures ranging from 600 to 900°C in air for 1 hour. The composition, microstructure, and mechanical properties of the films were characterized by energy dispersive x-ray spectroscopy, x-ray diffraction, scanning electron microscopy, and nanoindentation. It reveals that under the template effect of TiAlN layers in multilayers, as-deposited amorphous Si3N4 is crystallized and grows coherently with TiAlN layers when Si3N4 layer thickness is below 0.6 nm. Correspondingly, the hardness and elastic modulus of the multilayers increase significantly. With further increase in the layer thickness, Si3N4 transforms into amorphous, resulting in a decrease of hardness and modulus. The TiAlN/Si3N4 nano-multilayers could retain their superlattice structure even up to 900°C. The small decrease in the hardness of multilayers annealed below 800°C was correlated to the release of compressive stress in multilayers. However, oxidation was found on the surface of multilayers when annealed at 800°C, which resulted in a marked decrease in the hardness of multilayers. The multilayers presented higher hardness as compared with the monolithic TiAlN film.

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Zhang, Chao, Lijun Shao, Yuming Dai, Duo Li, and Yuan Chen. "Individual Layer Thickness Dependence of Microstructure and Mechanical Properties of Magnetron Sputtering Mo-W-Doped Ni/Ni3Al Multilayers." Coatings 12, no. 11 (October 24, 2022): 1616. http://dx.doi.org/10.3390/coatings12111616.

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The mechanical properties of nanocrystalline pure Ni films are degraded due to grain coarsening with exposure for a long time in ambient. In order to further improve the mechanical properties of Ni-based thin films, as-sputtered Mo-W co-doped Ni/Ni3Al multilayered structures were constructed. When the individual layer thickness (h) is lower than 40 nm, both the average grain sizes and the crystallinity degrees are degraded, showing a tendency for the formation of the amorphous phase. With h = 40 nm, nano-twins were observed as (111) twining interfaces for the multilayers due to the reduction of the stacking fault energy by the co-doping of Mo-W, whereas the nucleation and growth of the nano-twins were limited, without observations for the Mo-W co-doped Ni/Ni3Al multilayer with h = 10 nm. The hardness of the multilayers was enhanced, and the elastic modulus was reduced at a lower h, owing to the grain refinements and layer interface barriers for strengthening, and the existence of the amorphous phase with the inferior modulus, respectively. The resistance against the fracture was enhanced due to toughening by the lamellar structure for the Mo-W doped Ni/Ni3Al multilayer at h ≤ 40 nm. Comprehensively, the Mo-W-doped Ni/Ni3Al multilayer with 10 nm displays a superior mechanical performance.

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21

Zhao, Mingyan, Reema Anouz, and Thomas Groth. "Effect of microenvironment on adhesion and differentiation of murine C3H10T1/2 cells cultured on multilayers containing collagen I and glycosaminoglycans." Journal of Tissue Engineering 11 (January 2020): 204173142094056. http://dx.doi.org/10.1177/2041731420940560.

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Polyelectrolyte multilayer coating is a promising tool to control cellular behavior. Murine C3H10T1/2 embryonic fibroblasts share many features with mesenchymal stem cells, which are good candidates for use in regenerative medicine. However, the interactions of C3H10T1/2 cells with polyelectrolyte multilayers have not been studied yet. Hence, the effect of molecular composition of biomimetic multilayers, by pairing collagen I (Col I) with either hyaluronic acid or chondroitin sulfate, based primarily on ion pairing and on additional intrinsic cross-linking was studied regarding the adhesion and differentiation of C3H10T1/2 cells. It was found that the adhesion and osteogenic differentiation of C3H10T1/2 cells were more pronounced on chondroitin sulfate-based multilayers when cultured in the absence of osteogenic supplements, which corresponded to the significant larger amounts of Col I fibrils in these multilayers. By contrast, the staining of cartilage-specific matrixes was more intensive when cells were cultured on hyaluronic acid-based multilayers. Moreover, it is of note that a limited osteogenic and chondrogenic differentiation were detected when cells were cultured in osteogenic or chondrogenic medium. Specifically, cells were largely differentiated into an adipogenic lineage when cultured in osteogenic medium or 100 ng mL−1 bone morphogenic protein 2, and it was more evident on the oxidized glycosaminoglycans-based multilayers, which corresponded also to the higher stiffness of cross-linked multilayers. Overall, polyelectrolyte multilayer composition and stiffness can be used to direct cell–matrix interactions, and hence the fate of C3H10T1/2 cells. However, these cells have a higher adipogenic potential than osteogenic or chondrogenic potential.

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Wang, Tao, Enrique Serra Bachs, Joris de Grooth, and Wiebe M. de Vos. "Advanced Oxidation Processes Coupled to Nanofiltration Membranes with Catalytic Fe0 Nanoparticles in Symmetric and Asymmetric Polyelectrolyte Multilayers." Membranes 13, no. 4 (March 28, 2023): 388. http://dx.doi.org/10.3390/membranes13040388.

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The in situ synthesis of Fe0 particles using poly-(acrylic acid) (PAA) is an effective tool for fabricating catalytic membranes relevant to advanced oxidation processes (AOPs). Through their synthesis in polyelectrolyte multilayer-based nanofiltration membranes, it becomes possible to reject and degrade organic micropollutants simultaneously. In this work, we compare two approaches, where Fe0 nanoparticles are synthesized in or on symmetric multilayers and asymmetric multilayers. For the membrane with symmetric multilayers (4.0 bilayers of poly (diallyldimethylammonium chloride) (PDADMAC)/PAA), the in situ synthesized Fe0 increased its permeability from 1.77 L/m2/h/bar to 17.67 L/m2/h/bar when three Fe2+ binding/reducing cycles were conducted. Likely, the low chemical stability of this polyelectrolyte multilayer allows it to become damaged through the relatively harsh synthesis. However, when the in situ synthesis of Fe0 was performed on top of asymmetric multilayers, which consist of 7.0 bilayers of the very chemically stable combination of PDADMAC and poly(styrene sulfonate) (PSS), coated with PDADMAC/PAA multilayers, the negative effect of the Fe0 in situ synthesized can be mitigated, and the permeability only increased from 1.96 L/m2/h/bar to 2.38 L/m2/h/bar with three Fe2+ binding/reducing cycles. The obtained membranes with asymmetric polyelectrolyte multilayers exhibited an excellent naproxen treatment efficiency, with over 80% naproxen rejection on the permeate side and 25% naproxen removal on the feed solution side after 1 h. This work demonstrates the potential of especially asymmetric polyelectrolyte multilayers to be effectively combined with AOPs for the treatment of micropollutants (MPs).

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Buznikov, Nikita A., and Galina V. Kurlyandskaya. "A Model for the Magnetoimpedance Effect in Non-Symmetric Nanostructured Multilayered Films with Ferrogel Coverings." Sensors 21, no. 15 (July 29, 2021): 5151. http://dx.doi.org/10.3390/s21155151.

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Magnetoimpedance (MI) biosensors for the detection of in-tissue incorporated magnetic nanoparticles are a subject of special interest. The possibility of the detection of the ferrogel samples mimicking the natural tissues with nanoparticles was proven previously for symmetric MI thin-film multilayers. In this work, in order to describe the MI effect in non-symmetric multilayered elements covered by ferrogel layer we propose an electromagnetic model based on a solution of the 4Maxwell equations. The approach is based on the previous calculations of the distribution of electromagnetic fields in the non-symmetric multilayers further developed for the case of the ferrogel covering. The role of the asymmetry of the film on the MI response of the multilayer–ferrogel structure is analyzed in the details. The MI field and frequency dependences, the concentration dependences of the MI for fixed frequencies and the frequency dependence of the concentration sensitivities are obtained for the detection process by both symmetric and non-symmetric MI structures.

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24

Anyfantis, Dimitrios I., Alexandros Barnasas, Nikolaos C. Diamantopoulos, Constantinos M. Tsakiris, Georg Schmidt, Evangelos Th Papaioannou, and Panagiotis Poulopoulos. "Influence of Pt Ultrathin Interlayers on Magnetic Anisotropy in Ni/NiO Multilayers." Micro 4, no. 1 (February 29, 2024): 157–69. http://dx.doi.org/10.3390/micro4010011.

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Perpendicular magnetic anisotropy at transition metal/oxide interfaces plays a significant role in technological applications such as magnetic storage and spintronics. In this study, we investigate the effects of thermal annealing and Pt ultrathin interlayers on the magnetic anisotropy in Ni/NiO multilayers. Ni/NiO/Pt multilayers were fabricated via radiofrequency magnetron sputtering and natural oxidation. The static magnetic properties of the samples were studied using temperature-dependent SQUID magnetometry. We focus on a sample with a Nickel thickness of 6.7 nm in each multilayer period. This multilayer in Ni/NiO form showed the maximum enhancement of perpendicular magnetic anisotropy after mild thermal annealing in past work. In this work, we study the effects of ultrathin Pt interlayers on the magnetic properties of such a Ni/NiO multilayer before and after annealing. We have observed a further increase in perpendicular magnetic anisotropy, and we study the temperature-dependent magnetic properties of this system, which combines the favorable magnetic properties of Ni/Pt and Ni/NiO multilayers.

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Li, Y. P., X. F. Zhu, J. Tan, B. Wu, W. Wang, and G. P. Zhang. "Comparative investigation of strength and plastic instability in Cu/Au and Cu/Cr multilayers by indentation." Journal of Materials Research 24, no. 3 (March 2009): 728–35. http://dx.doi.org/10.1557/jmr.2009.0092.

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The mechanical response to indentation (including nano- and microindentation) has been investigated in Cu/Au and Cu/Cr multilayers with respective layer thickness ratios of 1:1 and 2:1, and individual layer thickness ranging from nanometer to submicrometer scale. It was found that the Cu/Cr multilayer has higher strength than the Cu/Au multilayer, although both multilayers have close Hall–Petch slope. Examination of indentation-induced deformation behavior shows that the Cu/Cr multilayer exhibits higher resistance to plastic deformation instability than the Cu/Au multilayer. Theoretical analysis indicates that the significant difference in mechanical response originates from the constituent layer configuration and interface structures, which impose distinguishing confining effect on dislocation activity.

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Tekgül, Atakan, Hakan Kockar, Hilal Kuru, and Mursel Alper. "Electrochemical Deposition of CoCu/Cu Multilayers: Structural and Magnetic Properties as a Function of Non-magnetic Layer Thickness." Zeitschrift für Naturforschung A 73, no. 2 (January 26, 2018): 127–33. http://dx.doi.org/10.1515/zna-2017-0332.

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AbstractElectrochemical deposition of CoCu/Cu multilayers was performed on titanium substrates from a single bath as a function of the Cu layer thicknesses. The deposition potentials were selected as −1.5 V for the magnetic layers and −0.3 V for the non-magnetic layers with respect to the saturated calomel electrode. The current-time transients were obtained during the deposition process, and the Co layer deposition and capacitive transients were calculated. On the basis of structural analysis, the multilayers were found to be polycrystalline with both Co and Cu layers adopting the face-centered cubic structure. The calculated lattice parameters of the multilayers slightly increase from 0.3585 to 0.3615 nm with increase in the Cu layer thickness, which is consistent with the bulk value of Cu. The inter-planar distance of the peaks of the multilayers is closer to that of Cu (d111=0.2087 nm) and Co (d111=0.2046 nm), and they become close to that of bulk Cu with increasing Cu layer thickness. In magnetic measurements, the magnetization decreases from 156 to 44 emu/cm3 depending on the Cu layer thickness. Furthermore, the coercivity of the multilayers increases from 20 to 140 Oe. These values show that the magnetic behaviour of the multilayers lie between those of soft and hard magnetic materials, but the multilayer having 2.5 nm Cu layer thickness shows hard magnetic property. For the CoCu(4 nm)/Cu(0.7 nm) multilayer, the magnetoresistance measurement shows 5.5 % giant magnetoresistance (GMR).

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Zhang, Chao, Lishuai Xie, and Dongdong Zhang. "The Effect of Individual Layer Thickness on Chemical Ordering of Ni-Based Multilayers." Journal of Nanoelectronics and Optoelectronics 15, no. 6 (June 1, 2020): 714–19. http://dx.doi.org/10.1166/jno.2020.2825.

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The microstructural evolution of magnetron sputtered Ni-based multilayers with different individual layer thicknesses h is investigated. The average grain size of multilayers and formation of chemical ordered Ni3Al phase are dependent on h in annealed Ni-based multilayer system which are disclosed by X-ray diffraction and transmission electron microscopy. Transformation of chemical ordering in the annealed multilayers is facilitated by large grains with lower density of grain boundaries when h ≥ 40 nm. On the contrary, when h < 40 nm, the retained disordered FCC Ni(Al) phase in the annealed Ni-based multilayers is attributed to the twin interface. The ordering mechanism can be explained by interface-controlled formation and migration of vacancies.

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He, J. L., W. Z. Li, and H. D. Li. "Simulation of nacre with TiN/Pt multilayers and a study of their hardness." Journal of Materials Research 12, no. 11 (November 1997): 3140–45. http://dx.doi.org/10.1557/jmr.1997.0410.

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TiN/Pt multilayers with individual thicknesses between 1 and 8 nm were prepared by ion beam sputtering deposition to simulate the micro-laminated architecture of nacre. Multilayer hardness and the laminated structure were investigated. It was found that sharp but incoherent interfaces were formed between individual layers. The multilayer hardness had strong dependence on layer arrangement. The range of layer thickness appropriate for high hardness was experimentally determined. Hardness enhancement of 30–70% was generally observed. With the layer thickness properly adjusted, the multilayer can even be harder than the hard component (TiN). Annealing experiments indicated that the hardness enhancement was an intrinsic property of the TiN/Pt multilayers.

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Ramos, Ana Sofia, Sónia Simões, Lukasz Maj, Jerzy Morgiel, and Maria Teresa Vieira. "Effect of Deposition Parameters on the Reactivity of Al/Ni Multilayer Thin Films." Coatings 10, no. 8 (July 23, 2020): 721. http://dx.doi.org/10.3390/coatings10080721.

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Nanoscale multilayers can be used as highly localized heat sources, making them attractive for several applications, in particular for joining and as igniters. Over the last decades, academia and industry have given particular emphasis to nanoscale multilayers from the Ni–Al system. In this study, Al/Ni (V) multilayer thin films with periods of nominally 25 and 50 nm (bilayer thickness) and near equiatomic average stoichiometry were produced by d.c. magnetron sputtering from Al (99.999% pure) and Ni (93 wt % Ni, 7 wt % V) targets (vanadium was added to the Ni target to make it non-magnetic). Deposition parameters such as the substrate rotation speed and substrate bias were varied in order to evaluate their effect on the reactivity of the multilayers. The influence of in situ ion bombardment of the multilayer thin films was also studied. Phase identification was carried out by X-ray diffraction, while the microstructure was analyzed in detail by transmission electron microscopy, distinguishing alternating layers throughout the entire thickness of the films. Although the films mainly consist of Al- and Ni-rich layers, the presence of the Al3Ni intermetallic phase was detected, except in the multilayers produced with the ion gun switched on during the deposition process. The ion bombardment, as well as the increase of the substrate bias, promote some microstructural disorder and thus affect the multilayers’ reactivity.

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Kot, Marcin, Kinga Chronowska-Przywara, Łukasz Major, and Juergen Lackner. "Adhesion of Cr/CrN Multilayers to Steel Substrates." Applied Mechanics and Materials 759 (May 2015): 27–35. http://dx.doi.org/10.4028/www.scientific.net/amm.759.27.

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Cr/CrN multilayers with a bilayer period λ = 62 ÷ 1000nm, were investigated. They were deposited by PLD technique on austenitic and ferritic stainless steel substrates. Coating hardness and adhesion to substrates were measured by nanoindentation and scratch testing. Multilayer properties were compared with single Cr and CrN coatings. The 2xCr/CrN and 4xCr/CrN multilayers exhibited hardness slightly lower than the hardness of a single CrN coating, while the critical load of the 4xCr/CrN multilayer, measured in the scratch test, was two times higher than for CrN. Furthermore, the character of coating failure also indicates the higher fracture toughness of multilayers than ceramic ones. The highest scratch resistance of the hardest multilayer with a bilayer period λ = 250nm is extremely interesting. The measured values of the critical loads LC1and LC2of all coatings were higher for harder ferritic than austenitic substrates. However, analysis of scratch track geometry indicated that coating failure occurred under the same deformation of the coating-substrate system, while the higher values of critical load for coatings on ferrite derived from the higher hardness of the substrate.

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Zhu, Jingtao, Jiayi Zhang, Haochuan Li, Yuchun Tu, Jinwen Chen, Hongchang Wang, Sarnjeet S. Dhesi, Mingqi Cui, Jie Zhu, and Philippe Jonnard. "Improving the soft X-ray reflectivity of Cr/Ti multilayers by co-deposition of B4C." Journal of Synchrotron Radiation 27, no. 6 (October 9, 2020): 1614–17. http://dx.doi.org/10.1107/s1600577520011741.

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The `water window', covering 2.4–4.4 nm, is an important wavelength range particularly essential to biology research. Cr/Ti multilayers are one of the promising reflecting elements in this region because the near-normal-incidence reflectivity is theoretically as high as 64% at 2.73 nm. However, due to multilayer imperfections, the reported reflectivity is lower than 3% for near-normal incidence. Here, B and C were intentionally incorporated into ultra-thin Cr/Ti soft X-ray multilayers by co-deposition of B4C at the interfaces. The effect on the multilayer structure and composition has been investigated using X-ray reflectometry, X-ray photoelectron spectroscopy, and cross-section electron microscopy. It is shown that B and C are mainly bonded to Ti sites, forming a nonstoichiometric TiB x C y composition, which hinders the interface diffusion, supresses the crystallization of the Cr/Ti multilayer and dramatically improves the interface quality of Cr/TiB x C y multilayers. As a result, the near-normal-incidence reflectivity of soft X-rays increases from 4.48% to 15.75% at a wavelength of 2.73 nm.

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Uyanik, Zemzem, Fulya Turkoglu, Hasan Koseoglu, Merve Ekmekcioglu, Bengu Ata, Yasemin Demirhan, Mehtap Ozdemir, Gulnur Aygun, and Lutfi Ozyuzer. "Enhanced optoelectronic properties of magnetron sputtered ITO/Ag/ITO multilayers by electro-annealing." Journal of Vacuum Science & Technology B 40, no. 4 (July 2022): 042204. http://dx.doi.org/10.1116/6.0001868.

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Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO) multilayers have attracted much attention to fulfill the growing need for high-performance transparent conducting oxide electrodes. To make these transparent multilayers work better, electro-annealing, which is a method of self-heating by electric current, can be effective. Moreover, the effect of current on ITO/Ag/ITO multilayers should be investigated to make sure that electronic devices will be reliable over their lifetime. In this study, ITO/Ag/ITO multilayer electrodes with varying Ag thicknesses were grown by DC magnetron sputtering at room temperature. Structural, optical, and electrical properties of these multilayers were investigated before and after electro-annealing. Measurement results revealed that improved optical transmittance and sheet resistance can be obtained by the optimization of Ag thickness for the as-grown ITO/Ag/ITO layers. The highest figure of merit (FoM) value of 17.37 × 10−3 Ω−1 with optical transmittance of 85.15% in the visible region and sheet resistance of 11.54 Ω/□ was obtained for the Ag thickness of 16.5 nm for as-grown samples. The electro-annealing of as-grown ITO/Ag/ITO multilayers led to improved optical behavior of the multilayer structure over a wide spectral range, especially in the near-infrared range. Electro-annealing also provided an improvement in the crystallinity and sheet resistance of the electrodes. The improvement of the electrical and optical properties of the structure enabled a FoM of 23.07 × 10−3 Ω−1 with the optical transmittance of 86.80% in the visible region and sheet resistance of 10.52 Ω/□. The findings of this work provide proper knowledge of the properties of ITO/Ag/ITO multilayers under electrical current and suggest that the overall performance of the multilayers can be improved by the electro-annealing process.

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Lai, Bo, Runze Qi, Zengbo Zhang, and Zhanshan Wang. "Study of Optical Performance and Structure of Yb/Al (1.5 wt.% Si) and Yb/Al (Pure) Multilayers Designed for the 73.6 nm Range." Coatings 14, no. 6 (May 23, 2024): 659. http://dx.doi.org/10.3390/coatings14060659.

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Yb/Al multilayer films exhibit excellent theoretical reflectivity in the 54–90 nm wavelength range. This study attempted to incorporate 1.5% wt.% of Si impurities into Al to suppress the crystallization of Al, reduce interfacial roughness, and enhance the actual reflectivity of the prepared Yb/Al multilayer films. Internal microstructure changes in the film layers before and after Si impurity doping were investigated using GIXRR, AFM, and XRD techniques. The reflectivity of two types of multilayer films, Yb/Al (1.5 wt.% Si) and Yb/Al (pure), was tested to evaluate the effect of Si impurity on film performance. The reflectivity of Yb/Al (1.5 wt.% Si) multilayers compared to Yb/Al (pure) multilayers increased by approximately 4%.

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34

Mesić, Mia, Tin Klačić, Anže Abram, Klemen Bohinc, and Davor Kovačević. "Role of Substrate Type in the Process of Polyelectrolyte Multilayer Formation." Polymers 14, no. 13 (June 24, 2022): 2566. http://dx.doi.org/10.3390/polym14132566.

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Polyelectrolyte multilayers are coatings formed by the alternate deposition of polycations and polyanions on a charged surface. In this study we examined how the type of substrate affects a multilayer prepared from poly(allylamine hydrochloride) and poly(acrylic acid). Silicon and titanium wafers were used as substrates. Their properties were systematically studied using ellipsometry, tensiometry, atomic force microscopy and streaming potential measurements. Multilayers were built up at pH = 7 with tetramethylammonium chloride as the background salt. The growth of films was monitored by ellipsometry, while the morphology and surface roughness were determined by atomic force microscopy. It was found that the thickness of multilayers containing 10 layers on silicon is 10 nm, whereas the thickness of the same film on titanium is three times higher. It was shown that multilayers formed on silicon display a grain-like structure, which was not the case for a film formed on titanium. Such morphological properties are also reflected in the surface roughness. Finally, it was shown that, in addition to the electrostatic interactions, the hydrophobicity of the substrate also plays an important role in the polyelectrolyte multilayer formation process and influences its thickness and properties.

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35

Sidelev, Dmitrii Vladimirovich, Sergey Evgeneyvich Ruchkin, Ivan Andreevich Shelepov, Nikolay Sergeevich Saburov, Andrey Gennadievich Malgin, Kirill Konstantinovich Polunin, Kirill Vicheslavovich Stoykov, and Andrey Andreevich Mokrushin. "Protective Cr Coatings with ZrO2/Cr Multilayers for Zirconium Fuel Claddings." Coatings 12, no. 10 (September 27, 2022): 1409. http://dx.doi.org/10.3390/coatings12101409.

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This article described the protective properties of Cr coatings with a barrier layer composed of ZrO2/Cr multilayers deposited onto E110 zirconium alloy. The coatings with a ZrO2/Cr multilayer thickness of 100, 250, and 750 nm and single-layer (1.5 µm) ZrO2 barrier were obtained by multi-cathode magnetron sputtering in Ar + O2 atmosphere. Then, cracking resistance and oxidation behavior were studied under conditions of thermal cycling (1000 °C) in air and high-temperature oxidation at 1200–1400 °C in a water steam. The role of the ZrO2/Cr multilayers and multilayer thickness on cracking resistance of the experimental coatings and oxidation resistance of the coated E110 alloy was discussed. It was shown that the coatings with more quantity of the ZrO2/Cr multilayers have higher cracking resistance, but such types of samples have a large amount of coating spallation under thermal cycling. The high-temperature steam oxidation (1200–1400 °C) demonstrated that interfaces of the ZrO2/Cr multilayers can act as a source of cavities formed by the Kirkendall mechanism that results in accelerating Cr–Zr interdiffusion for Cr-coated E110 alloy.

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36

Suzuki, Kosuke, Masaki Hayata, Katsuhiko Minegishi, Ryosuke Kondoh, Tadashi Kato, Kazushi Hoshi, Masayoshi Itou, Yoshiharu Sakurai, and Hiroshi Sakurai. "Study of Perpendicular Magnetic Anisotropy in Co/Au Multilayer Probed by Magnetic Compton Profile." Key Engineering Materials 596 (December 2013): 8–14. http://dx.doi.org/10.4028/www.scientific.net/kem.596.8.

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Magnetic Compton profiles (MCPs) of Co/Au multilayers have been measured and analyzed by DV-Xαcluster model calculations from a viewpoint of perpendicular magnetic anisotropy (PMA). The PMA and the MCPs are discussed for the presently obtained results for Co/Au, along with the previously obtained results for Co/Pd and Co/Pt. A Co/Au multilayer shows a weak PMA which is caused by |m|=1 states of Co 3d electrons at a smooth Co/Au interface. The increase of the interface-to-volume ratio plays the main role in determining the perpendicular anisotropy in Co/Au multilayers. The strain of a Co layer can have a secondary role in determining the magnetic anisotropy in Co/Au multilayers, although the strain dominates PMA in the case of Co/Pd and Co/Pt multilayers.

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37

Yamashita, K., H. Kunieda, Y. Tawara, and K. Tamura. "Multilayer X-Ray Optics for Future Missions." Symposium - International Astronomical Union 188 (1998): 337–38. http://dx.doi.org/10.1017/s0074180900115426.

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Multilayers have a great potentiality to improve the image quality, spectral resolution and energy coverage of x-ray optical systems. The angular resolution of a normal incidence telescope aims at approaching the diffraction limit in the soft x-ray region. Multilayer supermirror makes it possible to fabricate a grazing incidence telescope with high sensitivity in hard x-ray region. Multilayer coated gratings are also useful dispersive elements with high efficiency and spectral resolution in the 2-10keV region. The application of multilayers is expected to open up a new field in astronomical imaging and spectroscopic observations which are not accessible by present telescopes.

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Gîfu, Ioana Cătălina, Monica Elisabeta Maxim, Ludmila Otilia Cinteza, Marcela Popa, Ludmila Aricov, Anca Ruxandra Leontieș, Mihai Anastasescu, et al. "Antimicrobial Activities of Hydrophobically Modified Poly(Acrylate) Films and Their Complexes with Different Chain Length Cationic Surfactants." Coatings 9, no. 4 (April 11, 2019): 244. http://dx.doi.org/10.3390/coatings9040244.

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Multilayer films from hydrophobically modified poly(acrylic acid) (HMPA) and their complexes with cationic surfactants were successfully prepared using the layer-by-layer (LbL) method. Alkyl trimethylammonium bromide derivatives with various lengths of the hydrophobic chain (C10–C18) were used to interact with the HMPA polymer, generating highly hydrophobic domains in the films and contributing to the antimicrobial properties of the prepared coating. The antimicrobial efficiency against common pathogens such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans was investigated in relationship with the morphology and composition of the thin films. The wettability and roughness of the multilayered systems were evaluated using atomic force microscopy (AFM) and contact angle measurements. The effects of the microbial exposure on the surface properties of the prepared films were investigated in order to assess the stability of the HMPA-deposited multilayers and the durability of the antimicrobial activity. The hydrophobically modified films exhibited antimicrobial activity against the studied pathogens. The best efficiency was registered in the case of S. aureus, which showed an inhibition of growth up to 100% after 2 h. C. albicans proved to be less sensitive to the effect of the multilayers deposited from HMPA–surfactant complexes. These results suggest that HMPA and HMPA–surfactant complex LbL multilayer films can be used as promising materials in antimicrobial surface coatings with increased resistance to pathogens during exposure.

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Bonevich, J., D. van Heerden, and D. Josell. "Face-centered-cubic titanium: An artifact in titanium/aluminum multilayers." Journal of Materials Research 14, no. 5 (May 1999): 1977–81. http://dx.doi.org/10.1557/jmr.1999.0266.

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The present investigation is the first comprehensive comparative study of x-ray diffraction (XRD) and transmission electron microscopy (TEM) results to address the important issue of fcc Ti formation in nanoscale multilayers. Ti/Al multilayers with 7.2 and 5.2 nm composition modulation wavelengths were studied by reflection and transmission XRD as well as transmission electron diffraction (ED), high-resolution TEM, and energy-filtered TEM. Previous reports have claimed deposition of fcc Ti in multilayer systems. Our results demonstrate that the Ti in Ti/Al multilayers deposits in the hcp form and that fcc Ti is merely an artifact of producing specimens for cross-sectional TEM.

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40

Allred, D. D., J. Gonzalez-Hernandez, O. V. Nguyen, D. Martin, and D. Pawlik. "Raman scattering and x-ray diffraction characterization of amorphous semiconductor multilayer interfaces." Journal of Materials Research 1, no. 3 (June 1986): 468–75. http://dx.doi.org/10.1557/jmr.1986.0468.

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Raman spectroscopy (RS) and low-angle x-ray diffraction (LAXRD) have been used to characterize semiconductor multilayer interfaces. In the present study a model for Raman spectra of multilayers is developed and applied to the specific case of the interfaces of a-Si/a-Ge multilayers. Quantification of the “blurring” of interfaces is possible because peak heights in the Raman spectra of thin films are proportional to the number of scatterers, thus RS is capable of directly “counting” the total number of chemical bonds of a given type in the film. Multilayers, prepared by various deposition techniques, are compared. The relative roles of LAXRD and RS in investigating interfaces are contrasted. Several a-Si/a-Ge multilayers deposited by ultra-high vacuum (UHV) evaporation (MBD) are found to exhibit very regular periodicities and exceptionally sharp interfaces (<1.0 Å intermixing).

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Sarkar, P., A. Biswas, N. Abharana, S. Rai, M. H. Modi, and D. Bhattacharyya. "Interface modification of Cr/Ti multilayers with C barrier layer for enhanced reflectivity in the water window regime." Journal of Synchrotron Radiation 28, no. 1 (January 1, 2021): 224–30. http://dx.doi.org/10.1107/s1600577520013429.

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The influence of a carbon barrier layer to improve the reflectivity of Cr/Ti multilayers, intended to be used in the water window wavelength regime, is investigated. Specular grazing-incidence X-ray reflectivity results of Cr/Ti multilayers with 10 bilayers show that interface widths are reduced to ∼0.24 nm upon introduction of a ∼0.3 nm C barrier layer at each Cr-on-Ti interface. As the number of bilayers increases to 75, a multilayer with C barrier layers maintains almost the same interface widths with no cumulative increase in interface imperfections. Using such interface-engineered Cr/C/Ti multilayers, a remarkably high soft X-ray reflectivity of ∼31.6% is achieved at a wavelength of 2.77 nm and at a grazing angle of incidence of 16.2°, which is the highest reflectivity reported so far in the literature in this wavelength regime. Further investigation of the multilayers by diffused grazing-incidence X-ray reflectivity and grazing-incidence extended X-ray absorption fine-structure measurements using synchrotron radiation suggests that the improvement in interface microstructure can be attributed to significant suppression of inter-diffusion at Cr/Ti interfaces by the introduction of C barrier layers and also due to the smoothing effect of the C layer promoting two-dimensional growth of the multilayer.

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Taylor, Caitlin A., Eric Lang, Paul G. Kotula, Ronald Goeke, Clark S. Snow, Yongqiang Wang, and Khalid Hattar. "Helium Bubbles and Blistering in a Nanolayered Metal/Hydride Composite." Materials 14, no. 18 (September 18, 2021): 5393. http://dx.doi.org/10.3390/ma14185393.

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Helium is insoluble in most metals and precipitates out to form nanoscale bubbles when the concentration is greater than 1 at.%, which can alter the material properties. Introducing controlled defects such as multilayer interfaces may offer some level of helium bubble management. This study investigates the effects of multilayered composites on helium behavior in ion-implanted, multilayered ErD2/Mo thin film composites. Following in-situ and ex-situ helium implantation, scanning and transmission electron microscopy showed the development of spherical helium bubbles within the matrix, but primarily at the layer interfaces. Bubble linkage and surface blistering is observed after high fluence ex-situ helium implantation. These results show the ability of metallic multilayers to alter helium bubble distributions even in the presence of a hydride layer, increasing the lifetime of materials in helium environments.

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Aye, Moe M., Elmeri Rivasto, Mukarram Z. Khan, H. Rijckaert, H. Palonen, H. Huhtinen, Isabel Van Driessche, and P. Paturi. "Multilayering BZO nanocolumns with different defect densities for YBCO high field applications." New Journal of Physics 23, no. 11 (November 1, 2021): 113031. http://dx.doi.org/10.1088/1367-2630/ac3682.

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Abstract The multilayer structures of alternating superconducting YBCO films doped with different BZO nanocolumn densities were utilized. We show that using 50 nm thick layers increases J c in the whole angular range by maximum 40% as compared with 200 nm single layer BZO-doped or multilayers with smaller thickness. Multilayering is found to be most effective at high magnetic fields and temperatures. These results indicate that demonstrated multilayer structures are extremely attractive for various electrical power applications in the foreseeable future. The experimental outcomes are thoroughly discussed with the mechanisms of crystalline quality and flux pinning in YBCO with different BZO nanorod densities multilayers of varying thicknesses.

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WO, P. C., P. R. MUNROE, Z. F. ZHOU, Z. H. XIE, and K. Y. LI. "CROSS-SECTIONAL TRANSMISSION ELECTRON MICROSCOPY OF DEFORMED MICROSTRUCTURES IN MONOLITHIC AND MULTILAYER TiSiN/TiN FILMS." International Journal of Modern Physics B 24, no. 01n02 (January 20, 2010): 18–25. http://dx.doi.org/10.1142/s0217979210063934.

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The deformation microstructures generated by nanoindentation of multilayer coatings consisting of TiSiN layers alternating with ten TiN interlayers, were examined by cross-sectional transmission electron microscopy (XTEM). Two multilayered coatings were studied: a thin TiSiN coating interlayered with thick TiN interlayer and a thick TiSiN coating alternated with thin TiN layers. A monolithic TiSiN coating was also examined for comparison. Surface morphology of the samples was found to be variable. Both surface roughness and coating hardness increase with the thickness of the outermost TiSiN layer. All samples show columnar structures, and for the multilayer coatings, epitaxial growth of these columnar grains through the TiSiN / TiN multilayers was observed. Stair-shaped shear cracks can be seen in the multilayer coating alternated with thick TiN interlayers, whereas radial and edge cracks are observed in the coating multilayered with thin TiN layers and in the monolithic coating. TEM analysis also suggests that columnar grains help to resist the initiation of edge cracks. Compared to other studies on similar coating systems with fewer periods of interlayers, the deformation observed here appears less severe, indicating an improvement in the strength of the coating through increasing the number of interlayers.

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Kucharska, Barbara, Edyta Kulej, and Jarosław Kanak. "A Comparative Study on the Cu/Ni Multilayer Period Using Two X-Ray Wavelengths." Solid State Phenomena 163 (June 2010): 291–94. http://dx.doi.org/10.4028/www.scientific.net/ssp.163.291.

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This paper presents the results of X-ray research on the structure of Cu/Ni multilayers magnetron-deposited on a Si (100) substrate. The multilayers, each consisting of a hundred Cu/Ni double-layers, but with a variable thickness of the Ni (1,2÷3nm) sublayer, were investigated. The thickness of the Cu sublayer was the same for all multilayers investigated and equalled 2nm. X-ray measurements were taken using filtered radiation with λCu=0.15405 nm and λCo=0.17902nm. The coatings were examined in respect of the angle at which the (111) reflection and satellite peaks appeared together. The obtained reflections were fitted using the Pseudo Voight curves. The thickness of the multilayer periods, resulting from the analysis of the diffraction pattern obtained for the above wavelengths of radiation, was compared. The thicknesses closest to those assumed in the deposition process were obtained for multilayers examined using radiation with Cu and utilizing the position of both satellite peaks, and multilayers examined using radiation with Co and utilizing the position of the main Cu/Ni(111) reflection and the S-1 satellite reflection.

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WANG, H. F., Y. Z. ZHANG, L. H. LIU, D. P. LI, G. Y. WANG, H. Y. TIAN, and D. N. ZHENG. "TRANSPORT PROPERTIES OF La2-x1Srx1CuO4+δ/La2-x2Srx2CuO4+δ MULTILAYERS GROWN BY LASER ABLATION." International Journal of Modern Physics B 27, no. 15 (June 4, 2013): 1362029. http://dx.doi.org/10.1142/s0217979213620294.

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A series of La 2-x1 Sr x1 CuO 4+δ/ La 2-x2 Sr x2 CuO 4+δ multilayers were epitaxially grown on (001) LaSrAlO 4 and (001) SrTiO 3 substrates by laser ablation, where x1 = 0.0, 0.08 (underdoped) and x2 = 0.24, 0.32, 0.45 (over-doped). Before the depositions of each multilayer, all of the single layers were deposited and characterized, and then the multilayers were deposited by using the same deposition condition except shifting targets for laser ablation. These multilayers are highly c-axis oriented. Several modulation wavelengths of the sublayers were selected for preparing the multilayers. The resistance measurements of these single layered films of La 2-x1 Sr x1 CuO 4+δ, La 2-x2 Sr x2 CuO 4+δ, and multilayers of La 2-x1 Sr x1 CuO 4+δ/ La 2-x2 Sr x2 CuO 4+δ were performed and compared. The transport measurements suggest that the charge redistribution may be a dominant factor for the superconducting transition temperature in low temperatures.

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JIANG, HONGCHUAN, CHAOJIE WANG, WANLI ZHANG, and XU SI. "MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF Al/TaNx MULTILAYERS." Functional Materials Letters 03, no. 02 (June 2010): 131–33. http://dx.doi.org/10.1142/s1793604710000993.

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Al/TaN x multilayers were deposited on Al 2 O 3 wafers by DC reactive magnetron sputtering. Microstructure and electrical properties of the samples were investigated in detail. The results show that more compact and smoother surfaces than that of TaN x thin films can be obtained in the Al/TaN x multilayers. Metal Al phases precipitate out from all the Al/TaN x multilayer samples. The main phases in the Al/TaN x multilayers are poor nitrogen phases when sputtered at lower nitrogen partial flux. However, rich nitrogen phases gradually precipitate out from the samples at higher nitrogen partial flux. With the increase of the nitrogen partial flux from 2 to 6%, the resistivity of the Al/TaN x multilayers increases from 640 to 1170 μΩ · cm, and the temperature coefficient of resistance (TCR) of the samples increases from 46 to 350 ppm/°C. Compared with TaN x thin films, the resistivity and TCR of the Al/TaN x multilayers are all higher than those of the TaN x thin films.

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48

Erwin, Erwin. "Studies on Structural and Magnetic Properties in Co/Sm Multilayers." Jurnal Natur Indonesia 13, no. 1 (November 21, 2012): 13. http://dx.doi.org/10.31258/jnat.13.1.13-20.

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Co/Sm multilayer films with structure of 20 [Co (x nm)/Sm (1.2 nm)] where x = 1.1, 2.2 and 4.2 nm and 20[Co (4.2nm)/Sm (x nm)] where x=1.2 nm to 7.5 nm were fabricated using dc magnetron sputtering. Each multilayer filmconsisted of 20 bilayers of Co layers with various thicknesses sandwiched with Sm layers. The application of lowangle X-ray diffraction measurements to the characterization of these multilayers is described. The periodiclayered structure with sharp interfaces was observed for all multilayer films. The measured magnetization valuesare lower than the values calculated in terms of the nominal concentration of cobalt in the multilayers. This impliessignificant “mixing” at small film thickness. The formation of a high magneto crystalline anisotropy of CoSm alloyat the interfaces, as a result of interdiffusion between Co and Sm layers was considered to be responsible for theincrease of the coercivity for Co/Sm multilayer.

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49

P. Simanjuntak, Herbert. "Transmission of Polarized Electrons through Multilayered Spintronics." Journal of Modern Nanotechnology, April 7, 2024. http://dx.doi.org/10.53964/jmn.2024001.

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Objectives: We study transmission of polarized electrons through multilayered spintronics of the form of n-cell periodic (L/R)n and symmetric (L/R)nL multilayers. L and R are layers of ferromagnetic semiconductors or insulators. The multilayers are of arbitrary sizes with layer L of width a and layer R of width b. The number of cells n is arbitrary positive integer. For specific examples, we use ferromagnetic semiconductors Ga0.73Mn0.27N, In0.92Fe0.08As and Ga0.8Fe0.2N which have different sd-exchange energies. For the insulators, we use non-ferromagnetic insulator Al0.3Ga0.7As, and ferromagnetic insulator Al0.9Fe0.1Sb. Methods: For the purpose of the study, we will calculate transmission coefficients of polarized electrons through each multilayer by using the method of transfer matrix for finite periodic systems. Energy dependencies are analytically derived and generalize the transmission through several types of multilayered spintronics, accommodating an arbitrary number of cells and layer widths embedded between ferromagnetic semiconductors. Results will be derived for multilayers with ferromagnetic layers that are the same as or different from the ferromagnetic semiconductors embedded in the multilayer. Results: Various characteristics of transmissions are obtained from low transmissions to high transmissions with sharp peaks about certain energies, depending on the ferromagnetic semiconducting layers and the insulating layers being used for the multilayers. By varying the materials and sizes of the layers one can arrange desired transmissions such as those with high transmissions at resonances.

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50

Shima, M., L. Salamanca-Riba, and L. J. Swartzendruber. "Magnetoresistive Properties of Quasiperiodic Metallic Multilayers." MRS Proceedings 451 (1996). http://dx.doi.org/10.1557/proc-451-419.

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ABSTRACTFibonacci Ni/Cu multilayers were fabricated by electrodeposition for the first time. The deposition of these quasiperiodic as well as periodic multilayers was fully controlled by a computer. X-ray diffraction spectra from a quasiperiodic multilayer built up from blocks of Ni(8ML)/Cu(4.5ML) and Ni(8ML)/Cu(9ML) indicate that the multilayer is of good quality. Since a Fibonacci multilayer has a quasiperiodic nature, the magnetoresistance effect in this system is expected to give more information about the mechanism for magnetic interlayer coupling in the GMR effect. The magnetic and magnetoresistive properties of the quasiperiodic multilayer were compared with those of two periodic multilayers having the equivalent layer thicknesses as the blocks composing the quasiperiodic multilayer. The magnetic and electrical properties of the quasiperiodic multilayer are not the weighted average of the two periodic multilayers.

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Journal articles on the topic 'Multilayers'

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