Articles de revues : « Single Crystal Thin Film Growth »

1

Seifert, A., A. Vojta, J. S. Speck et F. F. Lange. « Microstructural instability in single-crystal thin films ». Journal of Materials Research 11, n^o 6 (juin 1996) : 1470–82. http://dx.doi.org/10.1557/jmr.1996.0183.

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Epitaxial PbTiO3 thin films were produced from a mixed Pb–Ti double-alkoxide precursor by spin-coating onto single crystal (001) SrTiO3 substrates. Heat treatment at 800 °C produces a dense and continuous, epitaxial lead titanate film through an intermediate Pb-Ti fluorite structure. A microstructural instability occurred when very thin single crystal films were fabricated; this instability caused the films to become discontinuous. Scanning electron microscopy and atomic force microscopy observations show that single crystal films with a thickness less than ∼80 nm developed holes that expose the substrate; thinner films broke up into isolated, single crystal islands. The walls of the holes were found to be (111) perovskite planes. A free energy function, which considered the anisotropic surface energies of different planes, was developed to describe the microstructural changes in the film and to understand the instability phenomenon. The function predicted that pre-existing holes greater than a critical size are necessary to initiate hole growth, and it predicted the observed morphological changes in the current system. Morphological stability diagrams that explain the stability fields for different film configurations, i.e., either completely covered, with holes, or single crystal islands, can be calculated for any film/substrate system.

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Cai, Chuanbing, et Hiroyuki Fujimoto. « Effects of Nd123/MgO Thin Film and MgO Single-crystal Seeds in Isothermal Solidification of YBaCuO/Ag ». Journal of Materials Research 15, n^o 8 (août 2000) : 1742–48. http://dx.doi.org/10.1557/jmr.2000.0251.

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The seeding effects of (001) Nd123/MgO thin films and MgO single crystals were studied in isothermal solidification of YBa2Cu3Oy composite with the additions of 40 mol% Y2BaCuO5, 10 wt% Ag, and 0.5 wt% Pt. Seeding with the Nd123/MgO thin film resulted in single-domain growth of Y123 crystal with a stable growth along the “100”?direction, while seeding with MgO single crystal produced multidomain growth in which the dominant growth facet is rotated 45° about (100) plane of MgO. Multidomain growth in MgO seeded sample was suppressed by decreasing undercooling degree. The effects of undercooling degree and seed size on multidomain growth are discussed in view of classical nucleation and growth theory.

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Ichikawa, Yoko, Toshiyuki Matsunaga, Mohsen Hassan, Isaku Kanno, Takaaki Suzuki et Kiyotaka Wasa. « Growth and structure of heteroepitaxial lead titanate thin films constrained by miscut strontium titanate substrates ». Journal of Materials Research 21, n^o 5 (1 mai 2006) : 1261–68. http://dx.doi.org/10.1557/jmr.2006.0162.

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Single-crystal lead titanate [(001)PbTiO3 (PT)] thin films were heteroepitaxially grown on a miscut strontium titanate [(001)SrTiO3 (ST)] substrate by radio frequency magnetron sputtering. The PT thin films were grown via a step-flow growth. The step-flow growth enhanced the layer growth resulting in the continuous (001) single-crystal structure without a dislocated interface for the film thickness below 200 to 250 nm. The PT thin films show a small temperature variation of the lattice parameters unlikely to the bulk PT crystals due to the substrate clamping. The temperature variation of the lattice constants is discussed in terms of the thermo-elastic deformation analysis for the PT/ST heterostructure.

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Chang, H. L. M., T. J. Zhang, H. Zhang, J. Guo, H. K. Kim et D. J. Lam. « Epitaxy, microstructure, and processing-structure relationships of TiO2 thin films grown on sapphire (0001) by MOCVD ». Journal of Materials Research 8, n^o 10 (octobre 1993) : 2634–43. http://dx.doi.org/10.1557/jmr.1993.2634.

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TiO2 thin films have been deposited on sapphire (0001) substrates under various conditions by metal-organic chemical vapor deposition. The structural properties of the deposited films were characterized by x-ray diffraction and transmission electron microscopy. The important growth parameters were found to be the deposition temperature and the deposition rate. The ranges studied for the two parameters were 400 to 850 °C and 10 to 120 Å/min, respectively. Depending on the growth conditions, most of the deposited films were either single-phase anatase or rutile, or a mixture of the two. These films were all epitaxial, but none of them were single-crystal films. Three distinct epitaxial relationships were observed between the films and the substrates, and, depending on the growth conditions, a deposited film can contain one, two, or all three of them. The fact that the films we obtained, although epitaxial, were never single crystal is explained based on the consideration of the difference in the rotational symmetries of the substrate surface and the film growth plane. We believe that it should be generally true that, in heteroepitaxial growth, a true single-crystal film can never be obtained as long as the point symmetry group of the substrate surface is not a subgroup of that of the film growth plane.

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Krakow, W., N. M. Rivera, R. A. Roy, R. S. Ruoff et J. J. Cuomo. « Epitaxial growth of C60 thin films on mica ». Journal of Materials Research 7, n^o 4 (avril 1992) : 784–87. http://dx.doi.org/10.1557/jmr.1992.0784.

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Single crystal films of C60 of different thickness values have been deposited on mica substrates by resistance evaporation. Electron diffraction and high resolution microscopy have been used to assess the orientational ordering and the nature of the defects present in these face-centered cubic films which exhibit a 〈111〉 direction normal to the film surface.

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Ohtake, Mitsuru, Shigeyuki Minakawa et Masaaki Futamoto. « Preparation of 3d Ferromagnetic Transition Metal Thin Films with Metastable bcc Structure on GaAs(100) Substrates ». Key Engineering Materials 605 (avril 2014) : 478–82. http://dx.doi.org/10.4028/www.scientific.net/kem.605.478.

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Ni, permalloy (Py: Ni - 20 at. % Fe), and Co films of 40 nm thickness are prepared on GaAs (100) single-crystal substrates at room temperature and 200 °C by magnetron sputtering. The growth behavior and crystallographic properties are studied. In early stages of film growth, metastable bcc single-crystals nucleate on the substrates for all the film materials. The crystal structure is stabilized through hetero-epitaxial growth. With increasing the thickness beyond 2 nm, the bcc structure starts to transform into fcc or hcp structure through atomic displacements parallel to the bcc {110} close-packed planes. The transformation orientation relationships are fcc {111}<10>, hcp {0001}<110> || bcc {110}<001>. The resulting Ni and Py films consist of a mixture of bcc and fcc phases, whereas the Co films involve an hcp phase in addition to the metastable bcc phase.

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Wang, Nan, Yu-Xiang Dai, Tian-Lin Wang, Hua-Zhe Yang et Yang Qi. « Investigation of growth characteristics and semimetal–semiconductor transition of polycrystalline bismuth thin films ». IUCrJ 7, n^o 1 (1 janvier 2020) : 49–57. http://dx.doi.org/10.1107/s2052252519015458.

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The preferred orientation growth characteristics and surface roughness of polycrystalline bismuth (Bi) thin films fabricated on glass substrates using the molecular beam epitaxy method were investigated at temperatures ranging from 18 to 150°C. The crystallization and morphology were analyzed in detail and the polycrystalline metal film structure-zone model (SZM) was modified to fit the polycrystalline Bi thin film. The boundary temperature between Zone T and Zone II in the SZM shifted to higher temperatures with the increase in film thickness or the decrease of growth rate. Furthermore, the effect of the thickness and surface roughness on the transport properties was investigated, especially for Bi thin films in Zone II. A two-transport channels model was adopted to reveal the influence of the film thickness on the competition between the metallic surface states and the semiconducting bulk states, which is consistent with the results of Bi single-crystal films. Therefore, the polycrystalline Bi thin films are expected to replace the single-crystal films in the application of spintronic devices.

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Miller, K. T., et F. F. Lange. « Highly oriented thin films of cubic zirconia on sapphire through grain growth seeding ». Journal of Materials Research 6, n^o 11 (novembre 1991) : 2387–92. http://dx.doi.org/10.1557/jmr.1991.2387.

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A two-step process has been developed to form highly oriented thin films in material systems with dissimilar crystal structures and interatomic spacings. This processing method utilizes current polycrystalline thin film deposition techniques. In this method, a polycrystalline thin film is first deposited and heat treated to promote its breakup into isolated grains. The breakup process favors those grains that have a low substrate interfacial energy and so produces a film of highly oriented but isolated grains. In the second process step, another polycrystalline thin film is deposited. The remnant grains act as seeds for the growth of a highly oriented thin film. The process is demonstrated through the growth of highly (100) oriented thin films of cubic ZrO2 (25 mol % Y2O3) on (0001) Al2O3 single crystal substrates, a material system in which film and substrate have dissimilar structures and interatomic spacings. Implications for the growth of epitaxial films using this method are discussed.

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Heimann, D., T. Wagner, J. Bill, F. Aldinger et F. F. Lange. « Epitaxial growth of β–SiC thin films on a 6H–SiC substrate using the chemical solution deposition method ». Journal of Materials Research 12, n^o 11 (novembre 1997) : 3099–101. http://dx.doi.org/10.1557/jmr.1997.0403.

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A polyvinylmethylsilane precursor has been used for the epitaxial growth of SiC thin films on 6H–SiC single crystal substrates. The films were prepared by dipping the single crystal 6H–SiC substrates into the precursor polymer solution with subsequent thermal treatments at different temperatures. Transmission electron microscopy (TEM) was used to characterize the microstructure and chemistry of the different SiC films. At 1100 °C, the film was amorphous and contained substantial oxygen. At 1600 °C, an epitaxial, single crystalline β–SiC film was observed.

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Tamaki, Jun, Gregory K. L. Goh et Fred F. Lange. « Novel epitaxial growth of barium titanate thin films by electrodeposition ». Journal of Materials Research 15, n^o 12 (décembre 2000) : 2583–86. http://dx.doi.org/10.1557/jmr.2000.0368.

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Electrodeposition was used to grow epitaxially BaTiO3 thin films on SrTiO3 single-crystal substrates with La0.7Sr0.3MnO3 (LSMO) conducting buffer layers. The epitaxial films appeared to consist of very small (ø10 nm) particles. The film completely covered the substrate when the reaction was performed at temperatures between 60 and 90 °C with LSMO potentials of –0.5 to –1.0 V against a Pt counter-electrode. It appeared that an electrophoretic force, acting on BaTiO3 nuclei within the solution, facilitated the deposition of the film.

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Yang, Tsung-Han, Chunming Jin, Ravi Aggarwal, R. J. Narayan et Jay Narayan. « On growth of epitaxial vanadium oxide thin film on sapphire (0001) ». Journal of Materials Research 25, n^o 3 (mars 2010) : 422–26. http://dx.doi.org/10.1557/jmr.2010.0059.

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We report the characteristics of epitaxial growth and properties of vanadium oxide (VO2) thin films on sapphire (0001) substrates. Pulsed laser deposition was used to grow (002) oriented VO2 films on sapphire (0001). Transmission electron microscopy studies showed that the orientation relationship between the substrate and the thin film is: (002)f2∥(0006)sub3 and [010]f2 ∥sub. It was also established that VO2 has three different orientations in the film plane which are rotated by 60° from each other. The epitaxial growth of vanadium oxide on sapphire (0001) has been explained in the framework of domain matching epitaxy (DME). Electrical resistivity measurements as a function of temperature showed a sharp transition with a hysteresis width ˜5 °C, and large resistance change (˜1.5 × 104) from the semiconductor phase to the metal phase. It is interesting to note that in spite of large angle twin boundaries in these VO2 films, the SMT characteristics are better than those observed for polycrystalline films. The higher width of thermal hysteresis for the VO2 film on c-sapphire compared to a bulk single VO2 crystal and a single-crystal VO2 film on r-sapphire can be attributed to the existence of these large-angle twin grain boundaries. These findings can provide insight into the phase transformation characteristics of VO2, which has important applications in switching and memory devices.

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12

Murakami, Toshiaki, et Minoru Suzuki. « Single-Crystal Thin-Film Growth and Properties of BaPb1-xBixO3 ». Japanese Journal of Applied Physics 24, S2 (1 janvier 1985) : 323. http://dx.doi.org/10.7567/jjaps.24s2.323.

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WASA, K., S. H. SEO, D. Y. NOH, I. KANNO et T. SUZUKI. « HETEROEPITAXIAL GROWTH OF STRESS FREE SINGLE CRYSTAL PEROVSKITE THIN FILMS ». Surface Review and Letters 13, n^o 02n03 (avril 2006) : 167–72. http://dx.doi.org/10.1142/s0218625x06008189.

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Thin films of single c-domain/single crystal ( PbMg 1/3 Nb 2/3 O 3)1-x( PbTiO 3)x, x = 0–0.4 (PMNT) were heteroepitaxially grown on (001) SrTiO 3 and (001) MgO substrates by magnetron sputtering using a quenching process. The lattice parameters of the quenched PMNT thin films were almost the same to the bulk values independently to the lattice parameters of substrates. The quenched PMNT thin films showed stress free structural properties, although the crystal structure of thin films is modified from bulk PMNT. The electromechanical properties are the same to the bulk single c-domain single crystals.

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Shaw, David T. « Controlled Growth of High-Temperature Superconducting Thin Films on Polycrystalline Substrates ». MRS Bulletin 17, n^o 8 (août 1992) : 39–44. http://dx.doi.org/10.1557/s0883769400041841.

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Since their discovery in 1987, significant progress has been made in the fabrication of high-quality, high-temperature superconducting (HTS) thin films. Films with reproducible properties can be routinely deposited on single crystal substrates by several well-established processing techniques. Single crystal substrates, however, are not suitable for many applications because of their cost, limitations in size and shape, and lack of flexibility. Hence, a great deal of effort has been directed at the fabrication of thin films on polycrystalline rather than single crystal substrates. For example, metallic substrates are expected to be useful for the fabrication of HTS conductors for such applications as generators, motors, and superconducting magnetic energy storage (SMES) devices. For polycrystalline thin-film applications, lattice matching for epitaxial growth of thin films is no longer possible. Microstructures of these films are generally more complex than those of single crystal films, primarily because of grain boundaries. As a result, the microstructure of polycrystalline films must be carefully controlled to ensure that the critical current density is high enough for practical applications.Happily, progress in this respect has been substantial. There have been laboratory demonstrations of techniques for controlled processing of high-quality HTS thin films on polycrystalline substrates. Even though the technology development in this area is still in its infancy, many successful processing approaches have been developed to set the stage for the eventual use of HTS thin films in power device applications.

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Grant Norton, M., et C. Barry Carter. « Observation of the early stages of heteroepitactic growth of BaTiO3 thin-films ». Journal of Materials Research 5, n^o 12 (décembre 1990) : 2762–65. http://dx.doi.org/10.1557/jmr.1990.2762.

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Thin-films of barium titanate (BaTiO3) have been deposited onto single-crystal MgO substrates using pulsed-laser ablation. The early stages of film growth have been examined using transmission electron microscopy by deposition of very thin films onto specially prepared electron transparent thin-foil substrates. The films, which were crystalline as deposited and close to stoichiometric composition, were formed by the nucleation and growth of small islands.

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Wasa, Kiyotaka, Isaku Kanno et Takaaki Suzuki. « Structure and Electromechanical Properties of Quenched PMN-PT Single Crystal Thin Films ». Advances in Science and Technology 45 (octobre 2006) : 1212–17. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1212.

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Thin films of single c-domain/single crystal (1-x)Pb(Mg1/3Nb2/3)O3－xPbTiO3 (PMN-PT), x≅0.33 near a morphotropic boundary (MPB) composition, were heteroepitaxially grown on (110)SRO/(001)Pt/(001)MgO substrates by magnetron sputtering. The heteroepitaxial growth was achieved by rf-magneron sputtering at the substrate temperature of 600oC. After sputtering deposition, the sputtered films were quenched from 600oC to room temperature in atmospheric air. The quenching enhanced the heteroepitaxial growth of the stress reduced single c-domain/single crystal PMN-PT thin films. Their electromechanical coupling factor kt measured by a resonance spectrum method was 45% at resonant frequency of 1.3GHz with phase velocity of 5500 to 6000m/s for the film thickness of 2.3μm. The d33 and d31 were 194pC/N and –104pC/N, respectively. The observed kt , d33 ,and d31were almost the same to the bulk single crystal values.

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Moustakas, Theodore D. « Molecular Beam Epitaxy : Thin Film Growth and Surface Studies ». MRS Bulletin 13, n^o 11 (novembre 1988) : 29–36. http://dx.doi.org/10.1557/s0883769400063892.

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Molecular Beam Epitaxy (MBE) is a thin film deposition process in which thermal beams of atoms or molecules react on the clean surface of a single-crystalline substrate, held at high temperatures under ultrahigh vacuum conditions, to form an epitaxial film. Thus, contrary to the CVD processes described in the other articles, the MBE process is a physical method of thin film deposition.The vacuum requirements for the MBE process are typically better than 10−10torr. This makes it possible to grow epitaxial films with high purity and excellent crystal quality at relatively low substrate temperatures. Additionally, the ultrahigh vacuum environment allows the study of surface, interface, and bulk properties of the growing film in real time, by employing a variety of structural and analytical probes.Although the MBE deposition process was first proposed by Günther in 1958, its implementation had to wait for the development of the ultrahigh vacuum technology. In 1968 Davey and Pankey successfully grew epitaxial GaAs films by the MBE process. At the same time Arthur's work on the kinetics of GaAs growth laid the groundwork for the growth of high quality MBE films of GaAs and other III-V compounds by Arthur and LePore and Cho.

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Song, Yiwen, Chi Zhang, James Spencer Lundh, Hsien-Lien Huang, Yue Zheng, Yingying Zhang, Mingyo Park et al. « Growth-microstructure-thermal property relations in AlN thin films ». Journal of Applied Physics 132, n^o 17 (7 novembre 2022) : 175108. http://dx.doi.org/10.1063/5.0106916.

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AlN thin films are enabling significant progress in modern optoelectronics, power electronics, and microelectromechanical systems. The various AlN growth methods and conditions lead to different film microstructures. In this report, phonon scattering mechanisms that impact the cross-plane (κz; along the c-axis) and in-plane (κr; parallel to the c-plane) thermal conductivities of AlN thin films prepared by various synthesis techniques are investigated. In contrast to bulk single crystal AlN with an isotropic thermal conductivity of ∼330 W/m K, a strong anisotropy in the thermal conductivity is observed in the thin films. The κz shows a strong film thickness dependence due to phonon-boundary scattering. Electron microscopy reveals the presence of grain boundaries and dislocations that limit the κr. For instance, oriented films prepared by reactive sputtering possess lateral crystalline grain sizes ranging from 20 to 40 nm that significantly lower the κr to ∼30 W/m K. Simulation results suggest that the self-heating in AlN film bulk acoustic resonators can significantly impact the power handling capability of RF filters. A device employing an oriented film as the active piezoelectric layer shows an ∼2.5× higher device peak temperature as compared to a device based on an epitaxial film.

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Ng, Man Fai, et Michael J. Cima. « Heteroepitaxial growth of lanthanum aluminate films derived from mixed metal nitrates ». Journal of Materials Research 12, n^o 5 (mai 1997) : 1306–14. http://dx.doi.org/10.1557/jmr.1997.0179.

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Epitaxial lanthanum aluminate (LaAlO3) thin films were deposited on single-crystal substrates by pyrolysis of spin-on mixed nitrate precursors. The films are epitaxial without any second phase. TEM micrographs show that all of these films have pores with sizes ranging from 5 to 30 nm. Grain boundaries are not observed. Selected area diffraction shows that the films are single-crystal-like, despite the porosity. All the films are smooth and crack-free. The precursors first decompose into an amorphous mixture. Heterogeneous nucleation occurs on the lattice-matched, single-crystal substrate surface. The epitaxial films grow upward and consume the amorphous regions. The crystallization temperature of LaAlO3 is lower for thin films than for bulk samples due to nucleation on the substrate. The crystallization of LaAlO3 does not exhibit linear growth kinetics. The Johnson–Mehl–Avrami exponent of growth is between 1.4 and 1.5. This deviation from the linear growth model (n = 1) can be attributed to continuous nucleation on the substrate/film interface.

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Kang, Geon-Hyeong, Ki Chul Jung, Jongbum Kim, JoonHyun Kang, In Soo Kim et Young-Hwan Kim. « Growth of High-Quality Perovskite KTa1-xNbxO3 Thin Films by RF Magnetron Co-Sputtering ». Coatings 12, n^o 11 (21 novembre 2022) : 1787. http://dx.doi.org/10.3390/coatings12111787.

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In this study, we demonstrate the growth of high-quality KTa1-xNbxO3 (KTN) thin films by using multi-target radio frequency (RF) magnetron co-sputtering with KTaO3, KNbO3, and K2CO3 targets. KTaO3 and KNbO3 targets were used to control the Ta/Nb ratio while the K2CO3 target was used to supply excess potassium (K) to compensate for the K deficiency. Through careful control of the RF powers applied to each target, high-quality perovskite KTN (x = 0.53) thin films were grown on various single crystal substrates. Variable temperature Raman spectroscopy revealed that the KTN thin films exhibit a ferroelectric phase at room temperature with a Curie temperature of ~403 K. The optical constants n and k of the KTN thin film were also similar to those reported for single KTN crystals. These results present a simple route toward fabricating high-quality perovskite KTN thin films with desired structural and optical properties for various device applications utilizing the RF magnetron co-sputtering method.

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He, Xi, Xiaotao Xu, Xiaoyan Shi et Ivan Božović. « Optimization of La2−xSrxCuO4 Single Crystal Film Growth via Molecular Beam Epitaxy ». Condensed Matter 8, n^o 1 (20 janvier 2023) : 13. http://dx.doi.org/10.3390/condmat8010013.

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Atomic layer-by-layer molecular beam epitaxy (ALL-MBE) combined with ozone is one of the best methods to fabricate single-crystal thin films of complex oxides. Cuprate such as La2−xSrxCuO4 (LSCO) is a representative complex-oxide high-temperature superconductor (HTS) material. Our group utilizes this method to produce high-quality single-crystal HTS films with atomically smooth surfaces and interfaces. In addition, ALL-MBE enables us to engineer multilayer heterostructures with atomic precision. This allows the fabrication of tunnel junctions, various nanostructures, and other HTS devices of interest for superconducting electronics. We have synthesized over three thousand LSCO thin films in the past two decades. These films’ structural and electronic properties have been studied and characterized by various methods. Here, we distill the extensive experience we accumulated into a step-by-step protocol to fabricate atomically perfect LSCO films. The recipe includes substrate preparation, ozone generation and distillation, source calibration, the in situ monitoring of the film synthesis, post-growth annealing, and ex situ characterization. It discloses a reproducible way to fabricate single-crystal LSCO films for basic research and HTS electronic applications.

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Grant Norton, M., James Bentley et Rand R. Biggers. « In Situ Electron Microscopy observations of structural transformations in single crystal lanthanum aluminate ». Proceedings, annual meeting, Electron Microscopy Society of America 53 (13 août 1995) : 238–39. http://dx.doi.org/10.1017/s0424820100137562.

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Single crystals of lanthanum aluminate (LaAlO3) are of interest as substrates to support the growth of films of the superconducting oxide YBa2Cu3O7. In order to facilitate epitaxy the thin films will often be deposited onto heated (T ≥ 700°C) substrates. LaAlO3 has a cubic structure at elevated temperatures and undergoes a transformation on cooling to the rhombohedral crystal structure-the stable form at room temperature. The phase transformation from the cubic to the rhombohedral structure leads to the formation of twins. The twin boundary is predominantly the (100) plane of the pseudo-cubic cell. Several potential problems associated with the phase transformation in LaA1O3 and the concomitant formation of twins have been postulated. Firstly, defects related to the twin boundaries might act as preferred nucleation sites during film deposition. Secondly, on cooling through the transformation temperature, after film deposition, twinning of the substrate might introduce strains into the thin film deposited on the initially untwinned substrate.

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Takeyama, Shojiro, Katsuyosi Watanabe et Teruo Komatsu. « Thin-Film Single-Crystal Growth of BiI3by a Hot Wall Technique ». Japanese Journal of Applied Physics 29, Part 1, No. 4 (20 avril 1990) : 710–17. http://dx.doi.org/10.1143/jjap.29.710.

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Komatsu, Keiji, Pineda Marulanda David Alonso, Nozomi Kobayashi, Ikumi Toda, Shigeo Ohshio, Hiroyuki Muramatsu et Hidetoshi Saitoh. « Epitaxial Growth of Magnesia Films on Single Crystalline Magnesia Substrates by Atmospheric-Pressure Chemical Vapor Deposition ». Journal of Materials Science Research 5, n^o 2 (31 janvier 2016) : 56. http://dx.doi.org/10.5539/jmsr.v5n2p56.

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<p class="1Body">MgO films were epitaxially grown on single crystal MgO substrates by atmospheric-pressure chemical vapor deposition (CVD). Reciprocal lattice mappings and X-ray reflection pole figures were used to evaluate the crystal quality of the synthesized films and their epitaxial relation to their respective substrates. The X-ray diffraction profiles indicated that the substrates were oriented out-of-plane during MgO crystal growth. Subsequent pole figure measurements showed how all the MgO films retained the substrate in-plane orientations by expressing the same pole arrangements. The reciprocal lattice mappings indicated that the whisker film showed a relatively strong streak while the continuous film showed a weak one. Hence, highly crystalline epitaxial MgO thin films were synthesized on single crystal MgO substrates by atmospheric-pressure CVD.</p>

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Ren, Shi Wei, Jing Wei Sun et Yan Zhong Hao. « Simulation of the Growth, Structure and Crystallization of the Amorphous Silicon Thin Film ». Advanced Materials Research 602-604 (décembre 2012) : 1457–60. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.1457.

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In this paper, using classical molecular dynamics, the growth of the amorphous silicon thin film deposited on the single crystal silicon is simulated and studied by Stillinger-Weber potential. The radial distribution functions of particles are calculated and the Voronoi diagrams of the films are given. The regular and irregular structures in the film are analyzed and the part crystallization condition is discussed. It is found that the features of the film are related with the ratio of the substrate temperature and the temperature of the incident atoms. The density of the deposited silicon film is obtained. The value of the density is about 2.2515g/cm3 which is consistent with the experiment data.

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Qiu, Yu, Peter Gerstel, Linqin Jiang, Peter Lipowsky, Luciana Pitta Bauermann et Joachim Bill. « Aqueous solution deposition of indium hydroxide and indium oxide columnar type thin films ». International Journal of Materials Research 97, n^o 6 (1 juin 2006) : 808–11. http://dx.doi.org/10.1515/ijmr-2006-0130.

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Abstract Crystalline In(OH)3 and UV-emitting In2O3 thin films with a unique columnar morphology have been successfully prepared for the first time via a simple aqueous solution deposition method. In the present study, sulfonate-terminated self-assembled monolayers on single-crystal Si wafers were used as substrates for the film deposition. Uniform In(OH)3 thin films formed on self-assembled monolayers in aqueous solutions of InCl3 · 4H2O at 60°C. These films, containing columnar In(OH)3 crystals, showed preferential growth orientation along the [100] direction. The current understanding of the film formation mechanism was discussed. After annealing in air at 400 °C, these films were converted to nanocrystalline In2O3 films without modification of the morphology. Photoluminescence emission from In2O3 films was reported at approximately 3.4 eV, which was ascribed to the near-band-edge emission.

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Kitahara, Gyo, Satoru Inoue, Toshiki Higashino, Mitsuhiro Ikawa, Taichi Hayashi, Satoshi Matsuoka, Shunto Arai et Tatsuo Hasegawa. « Meniscus-controlled printing of single-crystal interfaces showing extremely sharp switching transistor operation ». Science Advances 6, n^o 41 (octobre 2020) : eabc8847. http://dx.doi.org/10.1126/sciadv.abc8847.

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Meniscus, a curvature of droplet surface around solids, takes critical roles in solution-based thin-film processing. Extension of meniscus shape, and eventual uniform film growth, is strictly limited on highly lyophobic surfaces, although such surface should considerably improve switching characteristics. Here, we demonstrate a technique to control the solution meniscus, allowing to manufacture single-crystalline organic semiconductor (OSC) films on the highest lyophobic amorphous perfluoropolymer, Cytop. We used U-shaped metal film pattern produced on the Cytop surface, to initiate OSC film growth and to keep the meniscus extended on the Cytop surface. The growing edge of the OSC film helped maintain the meniscus extension, leading to a successive film growth. This technique facilitates extremely sharp switching transistors with a subthreshold swing of 63 mV dec−1 owing to the effective elimination of charge traps at the semiconductor/dielectric interface. The technique should expand the capability of print production of functional films and devices.

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Wang, Jing, Weiyuan Wang, Jiyu Fan, Huan Zheng, Hao Liu, Chunlan Ma, Lei Zhang et al. « Epitaxial growth and room-temperature ferromagnetism of quasi-2D layered Cr₄Te₅ thin film ». Journal of Physics D : Applied Physics 55, n^o 16 (24 janvier 2022) : 165001. http://dx.doi.org/10.1088/1361-6463/ac47c2.

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Abstract Large-scale growth of two-dimensional (2D) ferromagnetic thin films will provide an ideal platform for studying 2D magnetism and active spintronic devices. However, controllable growth of 2D ferromagnets over large areas faces tremendous challenges. Herein, we report a large-area growth of 2D ferromagnetic single-crystal thin films Cr4Te5 on Al2O3 (0001) substrates using pulsed laser deposition. X-ray diffraction patterns and atomic force microscopy detection confirm that all thin films have high quality epitaxy together with being atom-level smooth. Magnetic measurements show the persistence of ferromagnetic ordering state to above room temperature, with a Curie temperature ∼320 K, atomic magnetic moment ∼0.307 μ B /Cr, and the easy-magnetization axis in the film plane. Comparing with bulk Cr4Te5 single-crystal, the critical exponent β = 0.491 indicates that the magnetic interactions of the thin film obey the mean-field model rather than the 3D Heisenberg model. This work will open an avenue for growing large-scale 2D ferromagnets and developing room temperature 2D magnet-based nanodevices.

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Resel, Roland, Markus Koini, Jiri Novak, Steven Berkebile, Georg Koller et Michael Ramsey. « Epitaxial Order Driven by Surface Corrugation : Quinquephenyl Crystals on a Cu(110)-(2×1)O Surface ». Crystals 9, n^o 7 (22 juillet 2019) : 373. http://dx.doi.org/10.3390/cryst9070373.

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A 30 nm thick quinquephenyl (5P) film was grown by molecular beam deposition on a Cu(110)(2×1)O single crystal surface. The thin film morphology was studied by light microscopy and atomic force microscopy and the crystallographic structure of the thin film was investigated by X-ray diffraction methods. The 5P molecules crystallise epitaxially with (201)5P parallel to the substrate surface (110)Cu and with their long molecular axes parallel to [001]Cu. The observed epitaxial alignment cannot be explained by lattice matching calculations. Although a clear minimum in the lattice misfit exists, it is not adapted by the epitaxial growth of 5P crystals. Instead the formation of epitaxially oriented crystallites is determined by atomic corrugations of the substrate surface, such that the initially adsorbed 5P molecules fill with its rod-like shape the periodic grooves of the substrate. Subsequent crystal growth follows the orientation and alignment of the molecules taken within the initial growth stage.

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Grant Norton, M., et C. Barry Carter. « Nucleation and Heteroepitaxy of YBa2Cu3O7-δ thin films ». Proceedings, annual meeting, Electron Microscopy Society of America 48, n^o 4 (août 1990) : 88–89. http://dx.doi.org/10.1017/s0424820100173571.

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The nucleation and heteroepitactic growth of YBa2Cu3O7−δ thin-films has been studied by transmission electron microscopy (TEM). The films were formed by pulsed-laser ablation and then observed in the TEM without further sample preparation. Direct observation of the early stages of film growth is possible due to the utilization of a new specimen-preparation technique. The films were deposited directly onto specially prepared electron-transparent substrates. The substrate material used in this study was single-crystal, (001)-oriented MgO. The thin-foil substrates were prepared from bulk single-crystal substrates in the following manner. Discs of 3mm diameter were cored, polished and dimpled to produce a final sample thickness of 10 - 20μm. The samples were ion milled to perforation using 5 kV Ar+ ions, then chemically cleaned. The cleaned foils were annealed in air at 1350°C for 10min. The annealing temperature is such that sufficient atomic mobility enables the formation of a series of steps on the surface.

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Seifert, Andreas. « Epitaxial growth of PbTiO3 thin films on {100} SrTiO3 from solution precursors ». Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994) : 576–77. http://dx.doi.org/10.1017/s042482010017061x.

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A mixed Pb-Ti-alkoxide liquid precursor, prepared from lead acetate and titanium iso-propoxide was used to form single crystal PbTiO3 thin films epitaxially on {100} SrTiO3 substrates.A gravimetric analysis of the precursor determined its molarity to 0.55 mol/1 and was carried out by drying the alkoxide overnight and heating it to 600° C for one hour. X-ray diffraction showed the resulting PbTiO3 powder to be single phase perovskite. PbTiO3 thin films were formed by spincoating previously annealed (1400°C, 2h) single crystal SrTiO3 substrates. During this process the precursor dries to a gel-like amorphous solid film that pyrolizes and crystallizes to the oxide during heat-treatment. XRD, SEM, TEM and AFM were used to characterize the progress of the epitaxial layer formation as well as the microstructural evolution of films heated at increasing temperatures, ranging from 400°C to 800°C. For XRD Θ-2Θ scans on PbTiO3 thin films heated at temperatures of 450°C and above, only the {00l} tetragonal PbTiO3 reflections (CPTO=0.4153 nm) could be observed, indicating strongly oriented or epitaxial films ({h00} of PbTiO3 (aPTO=0.3899 nm) is masked by (MX)} of the SrTiO3 substrate (aSTO=0.3904 nm)).

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Chaudhuri, J., R. Thokala, J. H. Edgar et B. S. Sywe. « Characterization Of Single Crystal Epitaxial Aluminum Nitride Thin Films On Sapphire, Silicon Carbide And Silicon Substrates By X-Ray Double Crystal Diffractometry And Transmission Electron Microscopy ». Advances in X-ray Analysis 39 (1995) : 645–51. http://dx.doi.org/10.1154/s0376030800023077.

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Epitaxial AIN thin films grown on sapphire, silicon and silicon carbide substrates were studied using x-ray double crystal diffractometry and transmission electron microscopy to compare the structure, residual stress and defect concentration in these thin films. The AIN thin films was found to have a wurtzite type of structure with a small distortion in lattice parameters which results in a small residual stress of the order of 109 dynes/cm2 in the film. The strain due to lattice parameter mismatch between the substrate and film is too small to account for the residual stress present. The calculated stress from the difference in thermal expansion coefficients between the film and substrate agrees well with the experimental values. Both the x-ray and transmission electron microscopy measurements indicate a low defect density in the AIN thin film grown on 6H-SiC substrate which could be attributed to the small difference in lattice parameters between AIN and 6H-SiC. The defect density in the AIN thin film grown on other substrates were considerably higher. This is the first report of the successful growth of single crystal AIN thin films with such a low concentration of defect density.

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Endoh, Norifumi, Shoji Akiyama, Keiichiro Tashima, Kento Suwa, Takamasa Kamogawa, Roki Kohama, Kazutoshi Funakubo et al. « High-Quality Few-Layer Graphene on Single-Crystalline SiC thin Film Grown on Affordable Wafer for Device Applications ». Nanomaterials 11, n^o 2 (4 février 2021) : 392. http://dx.doi.org/10.3390/nano11020392.

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Graphene is promising for next-generation devices. However, one of the primary challenges in realizing these devices is the scalable growth of high-quality few-layer graphene (FLG) on device-type wafers; it is difficult to do so while balancing both quality and affordability. High-quality graphene is grown on expensive SiC bulk crystals, while graphene on SiC thin films grown on Si substrates (GOS) exhibits low quality but affordable cost. We propose a new method for the growth of high-quality FLG on a new template named “hybrid SiC”. The hybrid SiC is produced by bonding a SiC bulk crystal with an affordable device-type wafer and subsequently peeling off the SiC bulk crystal to obtain a single-crystalline SiC thin film on the wafer. The quality of FLG on this hybrid SiC is comparable to that of FLG on SiC bulk crystals and much higher than of GOS. FLG on the hybrid SiC exhibited high carrier mobilities, comparable to those on SiC bulk crystals, as anticipated from the linear band dispersions. Transistors using FLG on the hybrid SiC showed the potential to operate in terahertz frequencies. The proposed method is suited for growing high-quality FLG on desired substrates with the aim of realizing graphene-based high-speed devices.

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Cheng, Xiankun, Qiang Gao, Kaifeng Li, Zhongliang Liu, Qinzhuang Liu, Qiangchun Liu, Yongxing Zhang et Bing Li. « Enhanced Phase Transition Properties of VO2 Thin Films on 6H-SiC (0001) Substrate Prepared by Pulsed Laser Deposition ». Nanomaterials 9, n^o 8 (24 juillet 2019) : 1061. http://dx.doi.org/10.3390/nano9081061.

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For growing high quality epitaxial VO2 thin films, the substrate with suitable lattice parameters is very important if considering the lattice matching. In addition, the thermal conductivity between the substrate and epitaxial film should be also considered. Interestingly, the c-plane of hexagonal 6H-SiC with high thermal conductivity has a similar lattice structure to the VO2 (010), which enables epitaxial growth of high quality VO2 films on 6H-SiC substrates. In the current study, we deposited VO2 thin films directly on 6H-SiC (0001) single-crystal substrates by pulsed laser deposition (PLD) and systematically investigated the crystal structures and surface morphologies of the films as the function of growth temperature and film thickness. With optimized conditions, the obtained epitaxial VO2 film showed pure monoclinic phase structure and excellent phase transition properties. Across the phase transition from monoclinic structure (M1) to tetragonal rutile structure (R), the VO2/6H-SiC (0001) film demonstrated a sharp resistance change up to five orders of magnitude and a narrow hysteresis width of only 3.3 °C.

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Miller, K. T., F. F. Lange et D. B. Marshall. « The instability of polycrystalline thin films : Experiment and theory ». Journal of Materials Research 5, n^o 1 (janvier 1990) : 151–60. http://dx.doi.org/10.1557/jmr.1990.0151.

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Dense polycrystalline thin films of ZrO2 (3 and 8 mol % Y2O3) were produced by the pyrolysis of zirconium acetate precursor films, which were deposited on single crystal Al2O3 substrates by spin-coating aqueous solutions of zirconium acetate and yttrium nitrate. Dense films were heat treated to encourage grain growth. With grain growth, these films broke into islands of ZrO2 grains. Identical areas were examined after each heat treatment to determine the mechanism that causes the polycrystalline film to uncover the substrate. Two mechanisms were detailed: (a) for a composition which inhibited grain growth and produced a polycrystalline film with very small grains, the smallest grains would disappear to uncover the substrate, and (b) for a composition which did not inhibit grain boundary motion, larger grains grew by enveloping a smaller grain and then developed more spherical surface morphologies, uncovering the substrate at three grain junctions. In both cases, the breakup phenomenon occurred when the average grain size was larger than the film thickness. Thermodynamic calculations show that this breakup lowers the free energy of the system when the grain-size-to-film-thickness ratio exceeds a critical value. These calculations also predict the conditions needed for polycrystalline thin film stability.

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Shin, D. H., J. Silcox, S. E. Russek, D. K. Lathrop, B. Moeckly et R. A. Buhrman. « Quasi-epitaxial orientations of grains and structure of grain boundaries in YBa2Cu3O7−x thin films ». Proceedings, annual meeting, Electron Microscopy Society of America 48, n^o 4 (août 1990) : 4–5. http://dx.doi.org/10.1017/s0424820100173157.

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When a thin film is grown on a substrate with a large difference in lattice constants, the interface energy as a function of relative orientation shows several cusped minima. If the lattice mismatch is small, or if the growth temperature is high and the deposition rate is slow, most of the nucleated islands assume the orientation corresponding to the minimum interface energy, and a nearly single crystalline film is obtained. If the growth conditions are not so favorable, a polycrystalline film is obtained in which each of the grains may take a variety of orientations corresponding to local minima of interface energy. These relative orientations between the film and substrate determine the tilt angles at the grain boundaries.YBCO films grown on MgO at high temperatures or on SrTiO3 where the lattice mismatch is minimal are found to be nearly single crystal.

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Fave, A., S. Berger, A. Beaumont, B. Semmache, P. Kleimann, J. Linnroos et A. Laugier. « LPE growth of textured single crystal silicon thin film for PV applications ». Thin Solid Films 383, n^o 1-2 (février 2001) : 209–11. http://dx.doi.org/10.1016/s0040-6090(00)01619-9.

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Ito, Akihiko, Hiroshi Masumoto et Takashi Goto. « Morphology of Epitaxially Grown BaRuO₃ and CaRuO₃ Thin Films by Laser Ablation ». Key Engineering Materials 352 (août 2007) : 315–18. http://dx.doi.org/10.4028/www.scientific.net/kem.352.315.

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Epitaxial BaRuO3 (BRO) and CaRuO3 (CRO) thin films were prepared on (001), (110) and (111) SrTiO3 (STO) single-crystal substrates by laser ablation, and their microstructures and anisotropy of electrical conductivity were investigated. The (205) (104), (110) and (009) oriented BRO thin films, and (001), (110) and (110) oriented CRO thin films were grown epitaxially on (001), (110) and (111) STO substrates with in-plain orientation, respectively. The (009) BRO thin film and (001) CRO thin film has a flat surface result from a good lattice matching to STO substrates. The (205) (104) BRO thin film and (111) CRO thin film exhibited orthogonal- and hexagonal-shaped texture, respectively. The (110) BRO thin film and (110) CRO thin film showed an island growth due to (110) surface feature of cubic perovskite structure. Epitaxial BRO and CRO thin films have a high electrical conductivity with a metallic conduction, the (111) CRO thin films exhibited the highest conductivity of 1.4×105 S·m-1.

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Francis, Andrew J., et Paul A. Salvador. « Crystal orientation and surface morphology of face-centered-cubic metal thin films deposited upon single-crystal ceramic substrates using pulsed laser deposition ». Journal of Materials Research 22, n^o 1 (janvier 2007) : 89–102. http://dx.doi.org/10.1557/jmr.2007.0014.

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Cu, Pt, Ag, and Au were deposited on (100)-oriented ceramic substrates (SrTiO3, LaAlO3, and MgO). Over a wide range of temperatures (room temperature to 600 °C), Cu films were (100)-oriented and exhibited cube-on-cube epitaxy. Epitaxial Pt(100) films were obtained only at high temperature; oriented Pt(111) films were obtained at lower temperatures. Ag and Au were never obtained as purely (100)-oriented samples, although the amount of (100)-film increased with increasing temperature. Three-dimensional islands formed for all metals at higher temperatures, while flatter film surfaces developed at lower temperatures. At any given temperature, the surface roughness of films on SrTiO3(100) increased in the order Pt < Cu < Au < Ag. The variations in film structural characteristics are described well by considering the metals’ (i) surface/interfacial energies, (ii) surface energy anisotropies, and (iii) surface diffusion coefficients. Flat, epitaxial growth is promoted by low-energy interfaces, low surface energy anisotropies, and slow surface diffusion.

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Tu, Rong, Jin Huang, Song Zhang et Lian Meng Zhang. « Epitaxial Growth of Copper Film by MOCVD ». Key Engineering Materials 680 (février 2016) : 507–10. http://dx.doi.org/10.4028/www.scientific.net/kem.680.507.

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Copper thin films were deposited on single crystal sapphire substrate via metal-organic MOCVD using Cu (acac)2 as precursor. X-ray diffraction (XRD) and Scanning Electronic Microscope (SEM) were employed for studying preferred orientation and microstructure. Atomic Force Microscope was utilized in order to characterize roughness of copper thin layer. By calculation of the Gibbs free energy, the reactions have been deeply understood. Depositions were carried out at various substrate temperatures in the rage 473K to 673K. It has been revealed that temperature determined the orientation and microstructure of copper films. At 673K, copper films have exhibited preferred orientation, smooth surface and connected grains, which proved that this copper thin film can act as precursor. Based on the study of epitaxial growth of copper films, a schematic diagram of epitaxial growth relationship is suggested for the step by step depositions processes.

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Nashimoto, Keiichi, Michael J. Cima, Paul C. McIntyre et Wendell E. Rhine. « Microstructure development of sol-gel derived epitaxial LiNbO3 thin films ». Journal of Materials Research 10, n^o 10 (octobre 1995) : 2564–72. http://dx.doi.org/10.1557/jmr.1995.2564.

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Film growth and microstructural evolution were investigated for sol-gel derived LiNbO3 thin films deposited on lattice-matched single-crystal substrates. Epitaxial LiNbO3 films of about 100 nm nominal thickness were prepared by spin coating a solution of the lithium niobium ethoxide on sapphire (0001) substrates and annealing at 400 °C or 700 °C in a humidified oxygen atmosphere. These films exhibited an epitaxial relationship with the substrate of the type LiNbO3 (0001) || α-Al2O3 (0001) and LiNbO3 [100] || α-Al2O3 [100] as determined by x-ray pole figure analysis. Transmission electron microscopy indicated the epitaxial films annealed at 400 °C consisted of slightly misoriented ∼5 nm subgrains and of numerous ∼10 nm enclosed pores. The microstructure and orientation development of these films was consistent with a heteroepitaxial nucleation and growth mechanism, in which epitaxial nuclei form at the substrate surface and grow upward into an amorphous and porous intermediate film: Epitaxial films annealed at 700 °C contained larger 150-200 nm subgrains and pinholes. Misorientations between adjacent subgrains appeared to be significantly smaller in films annealed at 700 °C than those in films annealed at 400 °C. Hydrolysis of the alkoxide precursor solution prior to spin coating promoted the development of polycrystalline films on single-crystal sapphire substrates. Infrared spectra and thermal analysis indicated that, independent of the degree of the solution hydrolysis, nucleation of LiNbO3 was immediately preceded by decomposition of an amorphous carbonate intermediate phase.

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Huang, Jen Ching, Yi Chia Liao, Huail Siang Liu et Fu Jen Cheng. « The Study on Deposition Process and Mechanical Properties of Deposited Cu Thin Films Using Molecular Dynamics ». Advanced Materials Research 684 (avril 2013) : 37–41. http://dx.doi.org/10.4028/www.scientific.net/amr.684.37.

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This paper studies the deposition process and mechanical properties of Cu thin films deposited on single crystal copper substrates with various surface roughnesses by molecular dynamics (MD). In the effect of vacancy concentration (Cv) of substrate, the Young's modulus of sample decreased as the Cv of substrate increased but the adhesion force will increase as the Cv of substrate increases. The effect of substrate roughness on the peak intensity of crystal orientation has little. And the greater Cv of substrate, the surface roughness of the deposited thin film also increased. In the effect of numbers of deposited atoms, the deposited thin film thickness increases, the surface will be relatively flat and the Young's modulus will also increase. By the XRD pattern, the principal growth directions of thin film are the (220) and (200) in the early stage of growth during deposition. However, with the thickness increasing, the (111) will be the preferred orientation.

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Hwang, Cheol Seong, Mark D. Vaudin et Gregory T. Stauf. « Influence of substrate annealing on the epitaxial growth of BaTiO3 thin films by metal-organic chemical vapor deposition ». Journal of Materials Research 12, n^o 6 (juin 1997) : 1625–33. http://dx.doi.org/10.1557/jmr.1997.0222.

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BaTiO3 thin films were deposited by metal-organic chemical vapor deposition at 840 °C on two differently treated (100) MgO single crystal substrates. One MgO substrate was only mechanically polished and the other substrate was polished and then annealed at 1100 °C for 4 h in oxygen. Observation by transmission electron microscopy showed that the BaTiO3 thin film deposited on the unannealed substrate was fine-grained and that the whole film was epitaxial (100) in nature. In contrast, the film deposited on the annealed substrate consisted of large, (100)-oriented, epitaxial grains within which were distributed (110)-oriented grains with random in-plane orientations. These differences in BaTiO3 films deposited on differently treated substrates are discussed with reference to the surface structure of the MgO substrate and nucleation kinetics of BaTiO3 thin films on MgO.

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Zhang, Ying Xiao, Hong Li Suo, Yue Zhao, Min Liu, Rong Wang, Dong He, Lin Ma et Mei Ling Zhou. « Epitaxial Growth of CeO₂ Buffer Layers on Both YSZ Single Crystal and Textured Ni5W Substrates by MOD Method ». Materials Science Forum 546-549 (mai 2007) : 2011–14. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.2011.

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CeO2 has been considered as one of the most lattice compatible and chemically stable materials for YBa2Cu3O7-x coated conductors. In this paper, we presented the epitaxial growth of CeO2 thin film on both YSZ single crystal and cube textured Ni5W substrates by MOD method. Homogenous, crack-free and dense CeO2 thin films on both substrates with sharp biaxially cube texture were fabricated by post-annealing the precursor films at 1000-1150°C. For the CeO2 film on the textured Ni5W substrate, the FWHM values of (111) Phi-scan and (002) rocking curve were around 6°and 7°, respectively, the surface roughness was less than 2 nm over an area of 1μm×1μm observed by AFM. It was found that the CeO2 thin film improved both the in-plane orientation and surface roughness of the Ni5W substrate, indicating that the as deposited CeO2 films were suitable for the further growth of YBCO superconductor layer.

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Jokerst, N. M. « Integrated Optoelectronics Using Thin Film Epitaxial Liftoff Materials and Devices ». Journal of Nonlinear Optical Physics & ; Materials 06, n^o 01 (mars 1997) : 19–48. http://dx.doi.org/10.1142/s0218863597000034.

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The separation of single crystal thin film epitaxial compound semiconductor layers from a lattice matched growth substrate through selective etching, with subsequent bonding of the epitaxial thin film devices onto host substrates, is an emerging tool for multi-material, hybrid integration. Progress to date in this area, presented herein, includes advanced thin film devices, thin film material separation and device integration processing techniques, and thin film material and device integration with host substrates which include silicon circuitry, polymers, glass, and lithium niobate.

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Ojonugwa Daniel, Thomas, Uno Essang Uno, Kasim Uthman Isah et Umaru Ahmadu. « Structural and microstructural study of SnS thin film semiconductor of 0.2 ». International Journal of Physical Research 7, n^o 1 (27 mai 2019) : 26. http://dx.doi.org/10.14419/ijpr.v7i1.27700.

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SnS semiconductor thin film of 0.20, 0.25, 0.30, 0.35, 0.40 μm were deposited using aerosol assisted chemical vapour deposition (AACV) on glass substrates and were investigated for use in a field effect transistor. Profilometry, X-ray diffraction, Scanning electron microscope and Energy dispersive X-ray spectroscopy were used to characterise the structural and microstructural properties of the SnS semiconductor. The SnS thin film was found to initially consist of a single crystal at thickness of 0.20 to 0.25μm after which it becomes polycrystalline with an orthorhombic crystal structure consisting of Sn and S elements whose composition varied with increase in thickness. The SnS film of 0.4 μm thickness shows a more uniform grain distribution and growth with a crystal size of 60.57 nm and grain size of 130.31 nm signifying an optimum for the as deposited SnS films as the larger grains reduces the number of grain boundaries and charge trap density hence allowing charge carriers to move freely in the lattice thereby causing a reduction in resistivity, increase in conductivity of the films and enhanced energy band gap which are essentially parameters for a semiconductor material for application in a field effect transistor.

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Chien, A. T., L. Zhao, M. Colic, J. S. Speck et F. F. Lange. « Microstructural development of BaTiO3 heteroepitaxial thin films by hydrothermal synthesis ». Journal of Materials Research 13, n^o 3 (mars 1998) : 649–59. http://dx.doi.org/10.1557/jmr.1998.0081.

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The hydrothermal growth of epitaxial BaTiO3 thin films on single-crystal SrTiO3 substrates occurs by the island growth mode. The aqueous solution chemistry is found to control interfacial characteristics and plays an important role in controlling film formation and faceting. Island faceting can be changed by the introduction of additional cations during synthesis. Electrophoretic data, confirmed by adsorption measurements, show that barium is a potential determining counterion and adsorbs on SrTiO3 surfaces. Initial electrical measurements show that the BaTiO3 films have a dielectric constant of 141 with a loss tangent of 0.9 that decreases with heat treatment.

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Nutt, S. R., et David J. Smith. « High-resolution TEM of thin-film β-SiC interfaces ». Proceedings, annual meeting, Electron Microscopy Society of America 44 (août 1986) : 408–9. http://dx.doi.org/10.1017/s0424820100143638.

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Silicon carbide is a large band gap semiconductor under development for microelectronic device applications involving high temperatures, high frequencies, and high power. Single crystal thin films of high purity β-SiC can be fabricated by epitaxial CVD onto a <100> silicon wafer substrate. Epitaxial growth is achieved by a two-step process in which the surface of the silicon substrate is first converted to SiC by heating in the presence of hydrocarbon vapors, Despite the large lattice mismatch, this process results in an epitaxial film of β-SiC 10nm in thickness, upon which the SiC crystal is then chemically vapor deposited. Relatively thick (20 microns) crack-free films of SiC can thus be fabricated, although significant problems remain, such as lattice constant and thermal expansivity mismatches, and metallization and passivation of the surface. These reasons have provided the motivation for a detailed examination of interface structures in β-SiC thin films using HRTEM imaging of cross-sectional specimens.

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Saraf, L. V., Z. H. Zhu, C. M. Wang et M. H. Engelhard. « Microstructure and secondary phase segregation correlation in epitaxial/oriented ZnO films with unfavorable Cr dopant ». Journal of Materials Research 24, n^o 2 (février 2009) : 506–15. http://dx.doi.org/10.1557/jmr.2009.0054.

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Low solubility dopant-host systems are well suited to study secondary phase segregation-microstructure dependence. We discuss the effect of microstructure on secondary phase segregation in epitaxial/oriented ZnO thin films with Cr as an unfavorable dopant (Cr:ZnO). Since differences in thin film microstructure are a function of the substrate and its orientation, simultaneous chemical vapor depositions were carried out on single crystals of Si (100), c-axis oriented Al2O3 (c-ALO), and r-axis oriented Al2O3 (r-ALO) resulting in epitaxial film growth on r-ALO and c-axis oriented film growth on Si and c-ALO, with a difference in vertical grain boundary density. To enhance the analysis sensitivity to the microstructure difference, the thickness of Cr:ZnO films was maintained at ∼50 nm. High-resolution transmission electron microscopy (HRTEM) analysis indicates uniform stress distribution in Cr:ZnO grown on r-ALO. Surface sensitive x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS) techniques were utilized for analysis of the data. We observe that a higher grain boundary density and the presence of an amorphous layer at the interface for films grown on Si(100) single crystal led to interfacial Cr-based secondary phase segregation as opposed to lower grain boundary density and epitaxial films grown on c-ALO and r-ALO single crystals, respectively. We also discuss the effects of trace carbon solubility on the film microstructure/secondary phase segregation relationship.

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Pavlenko A.V., Stryukov D. V. et Kubrin S.P. « The phase composition and structure of the BiFeO-=SUB=-3-=/SUB=- film grown on MgO(001) substrate by high frequency cathode deposition in oxygen atmosphere ». Physics of the Solid State 64, n^o 2 (2022) : 206. http://dx.doi.org/10.21883/pss.2022.02.52969.215.

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The crystal structure and Mossbauer spectroscopy studies results for BiFeO3 film growth on the MgO(001) single crystal substrate are present in the paper. It been shown that film have high crystal perfection and low defectiveness which results in appearing of narrow lines during the theta-2theta and φ scanning and the small (lower than 0.7o) disorientation of film and substrate crystal axes. It is been revealed that unit cell of BiFeO3/MgO(001) heterostructure possess monoclinic symmetry and deformation of unit cell is negligible. The Mossbauer study shows that magnetic subsystem of film has spatial spin-modulated structure with zero value of anharmonicity parameter (m). This indicate that at room temperature the magnetic anisotropy changes from the "easy axis" type to "easy plane" type. Keywords: thin films, bismuth ferrite, Mossbauer effect.

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