Статті в журналах з теми "Binary Heusler Alloy"

Although Heusler alloys have been known for more than a century, but since the last decade there has been a quantum jump in research in this area. Heusler alloys show remarkable properties, such as ferromagnetic shape memory effect, magnetocaloric effect, half metallicity, and most recently it has been shown that it can be used for direct conversion of heat into electricity. Heusler alloys Ni-Mn-Z (Z=Ga, Al, In, Sn, Sb), show a reversible martensitic transformation and unusual magnetic properties. Other classes of intermetallic Heusler alloy families that are half metallic (such as the half Heusler alloys Ni-Mn-Sb and the full Heusler alloy Co2MnGe) are attractive because of their high Curie temperature and structural similarity to binary semiconductors. Unlike Ni-Mn-Ga, Ni-Mn-In and Ni-Mn-Sn transform from ferromagnetic austenite to non-ferromagnetic martensite. As is consistent with the Clausius-Clapeyron equation, the martensitic phase transformation can be manipulated by a magnetic field, leading to possible applications of these materials enabling the magnetic shape memory effect, energy conversion and solid state refrigeration. In this paper, we summarize the salient features of Heusler alloys, like the structure, magnetic properties and potential application of this family of alloys in industry.

Abstract Heusler alloys are a huge family of binary, ternary and quaternary compounds and contain a wide range of unique properties, which made Heusler compounds to be the efficient materials for diverse applications. When it comes to the commercial applications mechanical properties are worth of check on and turn out to be the significant factor in the processing and final use of the materials. These properties make the study proficient by examine the nature of material under external pressure. In this study, we estimated mechanical properties of Rh2MnZn full-Heusler alloy using the full-potential linearized augmented plane wave method (FP-LAPW) method within the density functional theory (DFT). We have obtained C11, C12 and C44 elastic constants due to cubic symmetry using Charpin method implemented in Wien2k code. Further, using these elastic constants mechanical properties such as bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, anisotropic factor and Cauchy’s pressure are calculated. These moduli depicted hardness, ductility and elastic anisotropy of the alloy.

AbstractIn this work, detailed first-principles calculations within the generalised gradient approximation (GGA) of electronic, structural, magnetic, and optical properties of Ni,Ti, and Al-based Heusler alloys are presented. The lattice parameter of C1b with space group F4̅3m (216) NiTiAl alloys is predicted and that of Ni2TiAl is in close agreement with available results. The band dispersion along the high symmetry points W→L→Γ→X→W→K in Ni2TiAl and NiTiAl Heusler alloys are also reported. NiTiAl alloy has a direct band gap of 1.60 eV at Γ point as a result of strong hybridization between the d state of the lower and higher valence of both the Ti and Ni atoms. The calculated real part of the dielectric function confirmed the band gap of 1.60 eV in NiTiAl alloys. The present calculations revealed the paramagnetic state of NiTiAl. From the band structure calculations, Ni2TiAl with higher Fermi level exhibits metallic properties as in the case of both NiAl and Ni3Al binary systems.

Hypothetical half-Heusler (HH) ternary alloy of CoVSn has already been computationally investigated for possible spintronics and thermoelectric applications. We report the experimental realization of this compound and the characterizations of its thermoelectric properties. The material was synthesized by a solid-state reaction of the stoichiometric amounts of the elements via powder metallurgy (30 h mechanical milling and annealing at 900 °C for 20 h) and spark plasma sintering (SPS). The temperature-dependent ternary thermodynamic phase diagram of Co-V-Sn was further calculated. The phase diagram and detailed analysis of the synthesized material revealed the formation of the non-stoichiometry HH CoVSn, mixed with the binary intermetallic phases of SnV3, Co2Sn, and Co3V. The combination of X-ray diffraction, energy-dispersive X-ray spectroscopy, and thermoelectric transport properties confirmed the formation of a multi-phase compound. The analysis revealed the predicted thermoelectric features (zT = 0.53) of the highly doped CoVSn to be compromised by the formation of intermetallic phases (zT ≈ 0.007) during synthesis. The additional phases changed the properties from p- to overall n-type thermoelectric characteristics.

The isothermal section of the Ni-Mn-Sb ternary system at 773 K was measured by means of 117 alloys which were analyzed by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and electron probe microanalysis (EPMA) techniques. The existence of 7 binary compounds, namely NiMn, Mn2Sb, MnSb, NiSb2, NiSb, Ni5Sb2, Ni3Sb and 2 ternary compounds, namely Ni2MnSb and NiMnSb were confirmed for this isothermal section. The four binary compounds Ni3Sb (Cu3Ti structure, Pmmn space group), Ni5Sb2 (Ni5Sb2-type structure, C2 space group), NiSb2 (FeS2-type structure, Pnnm space group) and Mn2Sb (Cu2Sb-type structure, P4/nmm space group) in the binary systems Ni-Sb and Mn-Sb were stoichiometric compounds, the homogeneity ranges of which were negligible. However the five single phases in the Ni-Mn system and the two binary compounds MnSb and NiSb showed more or less homogeneity ranges formed by substitution of Mn and Sb for Ni atom. The Heusler compound ? (Ni2MnSb) has L21-type ordered structure with space group Fm-3m, a = 0.6017 nm. And the crystal structure for the Half-Heusler compound ? (NiMnSb) is C1b-type (F-43m) with a = 0.5961 nm. The approximate homogeneity ranges of the two ternary compounds ? and ? at 773 K were investigated.

The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue, but it has an impact on the thermoelectric properties. In this study, two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973 K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni, Zr-Sn, and Ni-Sn. The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting. Solubilities of x<0.07 at 973 K and x<0.13 at 1173 K were clearly indicated. An intermediate-Heusler phase with a partly filled Ni void was observed, which is believed to be beneficial to the lowered lattice thermal conductivity. The highest ZT value~0.71 at 973 K was obtained for ZrNi1.11Sn1.04. The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.

The aim of the work is to search possibility for preparation of the Mn2VSn and V2MnSn Heusler-type compounds. We have carried out the 119Sn-Mössbauer spectroscopy, scanning electron microscopy and X-ray diffraction studies on the some Mn0.5V0.25 Sn0.25 and V0.5Mn0.25Sn0.25 solid solutions prepared by arc melting of the constituent metals. Combining an independent information about atomic structure from X-ray diffraction and Mössbauer spectroscopy it was possible to identify main chemical environments responsible for the magnetic ordering observed in the samples. The studies revealed that investigated alloys are characterized by existence of the binary compounds, namely V2Sn3, V3Sn and Mn3Sn, with different extension in Mn and V atomic concentration, respectively. No ternary compounds were found in investigated systems.

In this review, we consider state-of-the-art density functional theory (DFT) investigations of strongly correlated systems performed with the meta-generalized gradient approximation (meta-GGA) strongly constrained and appropriately normed (SCAN) functional during the last five years. The study of such systems in the framework of the DFT is complicated because the well-known exchange–correlation functionals of the local density approximation (LDA) and generalized gradient approximation (GGA) families are not designed for strong correlations. The influence of the exchange–correlation effects beyond classical LDA and GGA are considered in view of the prediction of the ground state structural, magnetic, and electronic properties of the magnetic materials, including pure metals, binary compounds, and multicomponent Heusler alloys. The advantages of SCAN and points to be enhanced are discussed in this review with the aim of reflecting the modern state of computational materials science.

Abstract The large acute myeloid leukemia (AML) patient-derived data sets collected within the European HARMONY alliance allows to study the molecular heterogeneity underlying AML in detail. Especially, how cytogenetic and molecular genetic aberrations differentially affect patients. Here, we report first results on the differences in mutational patterns in males and females. We studied a cohort of AML patients characterized by a panel of 70 molecular abnormalities comprising both cytogenetic and genetic observations. We quantified the differences of molecular patterns between sexes in two ways: 1) by comparing the number of gene-gene mutation co-occurrence and mutual mutation exclusivity with a χ 2 test, 2) exploiting the Hierarchical Dirichlet process (HDP) for molecular components discovery. In particular, we added sex as a further layer of the hierarchy allowing the same molecular components to be differently re-weighted based on gender. The HARMONY AML cohort comprised 2796 patients with detailed molecular information from targeted sequencing of 41 genes and detailed cytogenetic information condensed into 29 cytogenetic properties, known, a priori, to be relevant for the disease. Male to female ratio was 52% vs. 48% and median age was 52.0 (18.2 - 91.4) years. The entry data of the analysis were in the form of a binary matrix reporting the presence/absence of a given alteration in a patient. The χ 2 test based on the relative co-occurrence of mutation pairs suggested a significant difference between men and women solely for RUNX1 and NPM1. The number of co-occurrences was higher in male than in females. No significant mutual exclusive mutations were found between the populations. By using a two hierarchic levels HDP clustering we identified 11 overall molecular components shared by all AML patients. Six of these components are characterized by one or more genetic drivers, namely: NPM1, RUNX1, Complex-Karyotype-TP53, FLT3-IDH2, IDH2, CEPBA-biallelic, while the others were driven by cytogenetic abnormalities: t(6;9), t(8;21), inv(3), rearrangement of 11q23, inv(16). These results were in agreement with the current WHO AML classification and with other recent studies, which have attempted to improve stratification/classification of patients based on their molecular aberration patterns. While the molecular components were the same for all patients, major differences were observed in the contribution of NPM1 and RUNX1 components to males' and females' genotypes. On one side, NPM1 component has a double weight in females with respect to males. On the other hand, RUNX1 impacts males much more than females. The other aberrations were equally represented in both sexes. To test the robustness of the differences found between sexes, we compared these results with random splits of the datasets finding no differences in component weights, thereby validating our observations. Big data collections such as the HARMONY Alliance data base ensure data comparability via OMOP common data model harmonization approaches thereby offering the possibility to study large cohort that allow meaningful subgroup analyses such as the one focusing on gender imbalances. Proving the concept of the HARMONY Alliance data hub, our study confirms a female preponderance for NPM1 mutations and an association of RUNX1 mutations with male gender. Impact on patient outcome is currently evaluated and will be presented at the annual meeting. Figure 1 Figure 1. Disclosures Heckman: Celgene/BMS: Research Funding; Orion Pharma: Research Funding; Novartis: Research Funding; Oncopeptides: Consultancy, Research Funding; Kronos Bio, Inc.: Research Funding. Dombret: Abbvie: Honoraria; Amgen: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; NOVARTIS: Research Funding; pfizer: Honoraria, Research Funding; servier: Research Funding; BMS-Celgene: Honoraria; Daiichi Sankyo: Honoraria. Montesinos: Tolero Pharmaceutical: Consultancy; Agios: Consultancy; Stemline/Menarini: Consultancy; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Glycomimetics: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Sierra: Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Research Funding; Janssen: Other: Educational grant; Roche: Other: Educational grant; Pfizer: Honoraria; BMS Celgene: Honoraria, Research Funding; Alexion: Other: Educational grant; Amgen: Other: Educational grant; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mayer: Principia: Research Funding. Voso: Novartis: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Sanz: Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Boehringer Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Other: Travel, accommodations, and expenses; Helsinn Healthcare: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses, Research Funding. Calado: Novartis: Current Employment. Döhner: Agios and Astex: Research Funding; Daiichi Sankyo: Honoraria, Other: Advisory Board; Jazz Roche: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Janssen: Honoraria, Other: Advisory Board; Astellas: Research Funding; Celgene/BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Gaidzik: Pfizer: Speakers Bureau; Janssen: Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Heuser: BergenBio: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; BMS/Celgene: Research Funding; Bayer AG: Honoraria, Research Funding; Astellas: Research Funding; Daichi Sankyo: Honoraria, Research Funding; Karyopharm: Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Research Funding; Tolremo: Honoraria; AbbVie: Honoraria; Janssen: Honoraria. Haferlach: MLL Munich Leukemia Laboratory: Other: Part ownership. Sobas: Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Turki: CSL Behring: Consultancy; Jazz Pharma: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau. Schulze-Rath: Bayer: Current Employment. Hernández Rivas: Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees. Döhner: Abbvie: Honoraria, Research Funding; Agios: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Astellas: Honoraria, Research Funding; Astex Pharmaceuticals: Honoraria; AstraZeneca: Honoraria; Berlin-Chemie: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; GEMoaB: Honoraria; Gilead: Honoraria; Helsinn: Honoraria; Janssen: Honoraria; Jazz Pharmaceuticals: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Oxford Biomedica: Honoraria; Pfizer: Research Funding; Roche: Honoraria. Ossenkoppele: Abbvie, AGIOS, BMS/Celgene Astellas,AMGEN, Gilead,Servier,JAZZ,Servier Novartis: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Gilead: Consultancy, Honoraria. Bullinger: Menarini: Consultancy; Amgen: Honoraria; Hexal: Consultancy; Novartis: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Jazz Pharmaceuticals: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Astellas: Honoraria; Abbvie: Consultancy, Honoraria; Gilead: Consultancy; Sanofi: Honoraria; Seattle Genetics: Honoraria; Bayer: Research Funding.

AbstractHalf-Heusler compound TiNiSn is one of the most promising candidates of thermoelectric materials which can be used to directly convert the waste heat to clean electric energy at high temperatures (around 1000 K). Thermoelectric power generation is an appealing approach for conserving energy and preserving the global environment. Half-Heusler compounds have the cubic C1b type ordered structure and show semiconducting behavior when their valence electron count (VEC) is around 18. TiNiSn is the most attractive one not only because it has excellent thermoelectric properties but also it consists of eco-friendly elements which are neither toxic nor costly. However, TiNiSn has a bothersome problem that fabrication of single phase TiNiSn alloy is quite difficult. We have found that TiNiSn phase forms by the ternary peritectic reaction. Thereby, inevitable non-equilibrium solidification results in the formation of impurity coexisting phases which tend to decrease thermoelectric properties. In the present work, to establish the basis of new fabrication processes for TiNiSn alloys, we have started from the investigation on the diffusion paths which are closely related to the formation of TiNiSn phase. The diffusion behavior was evaluated using solid/liquid diffusion couples composed of the binary Ti-Ni intermetallic compounds and Sn liquid phase, where we have selected TiNi, TiNi3 and Ti2Ni as solid phases for instance. The most interesting result is that the single-phase TiNiSn phase layer forms at the TiNi/Sn(L) interface during annealing at 1073 K for only 1 h. Moreover, faceted grains of TiNiSn single-crystal grow at the interface toward the liquid Sn phase. We have confirmed two interesting microstructural features using EBSD analyses. One is that most of these TiNiSn single-crystals have the same crystallographic orientation, and the other is that TiNiSn phase layer formed on the TiNi side of the interface consists of very fine sub-microns grains. While TiNiSn solely forms at the TiNi interface, Heusler TiNi2Sn also forms with TiNiSn at the TiNi3 interface and Ti6Sn5 tends to coexist at the Ti2Ni interface.