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Heusler Compound: A Novel Material for Optoelectronic, Thermoelectric, and Spintronic Applications
Published in Niladri Pratap Maity, Reshmi Maity, Srimanta Baishya, High-K Gate Dielectric Materials, 2020
A Heusler compound is a name given to an intermetallic compound after a German mineralogist and a physicist Friedrich Heusler. Heusler reported that few alloys comprise copper, manganese, and ferromagnetic element despite of paramagnetic constituent (Heusler, 1903). Its magnetism varies considerably with heat treatment and composition (Knowlton, et al. 1912). In 1934, Bradley and Rogers discovered the ferromagnetic phase at room temperature with fully ordered structure of L21 type (Bradley, 1934). This system has a primitive cubic lattice of copper atoms with alternate body centered by manganese and aluminum. In order to solve this ferromagnetism, further insight of the solid properties were closely analyzed from experiment as well as theory. For instance, the prototype Heusler compound Cu2MnAl with fcc-L21 structure demonstrates a ferromagnetic configuration.
Benefits of the Selection and Use of High Entropy Alloys for High-Temperature Thermoelectric Applications
Published in T.S. Srivatsan, Manoj Gupta, High Entropy Alloys, 2020
Since the ktot is large for metallic materials, due to the large contribution from the ke, which results in very low Seebeck coefficients, metal alloys have mostly been avoided in the search for highly efficient thermoelectric materials. Some of the more well-known metal alloy compounds are half-Heusler compounds and quasi-crystals, where their inherent properties make them suitable as potential thermoelectric materials [3–7].
Effects of data bias on machine-learning–based material discovery using experimental property data
Published in Science and Technology of Advanced Materials: Methods, 2022
Masaya Kumagai, Yuki Ando, Atsumi Tanaka, Koji Tsuda, Yukari Katsura, Ken Kurosaki
The performance of thermoelectric materials was evaluated as a dimensionless figure of merit, zT=S2σ/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the temperature. The discovery of high-performance thermoelectric materials involves searching for materials with a high-power factor (PF = S2σ) and low κ. For several years, degenerate semiconductors based on heavy metals such as Bi, Pb, Te, and Sb have been the mainstream materials exhibiting high zT. Numerous other material systems, such as skutterudite and clathrate compounds, Zintl phase and Heusler compounds, and oxides and silicide compounds, have been reported as thermoelectric materials and are included in the dataset used in this study.
Theoretical investigations of physical properties of Pt-based half-Heusler alloys PtMnZ (Z = Se, Sn, Te) for spintronic applications
Published in Philosophical Magazine, 2022
M. B. Siad, A. Bekhti Siad, M. Baira, K. Bettir, S. Chadli
The present study reports the structural, mechanical, electronic and magnetic properties of half-Heusler alloys PtMnSe, PtMnSn and PtMnTe. The half-Heusler compounds crystallise in the face-centered-cubic (fcc) C1b structure with space group Fm (No. 216) [46]. The cubic unit cell is containing 12 atomic positions as seen in Figure 1. The energy of each unit cell is calculated by the FP-LAPW method within the DFT. To attain the optimisation of structure and geometry of the crystal, Birch Murnaghan’s equation of state [47] is used to fit the total energy with the change in the volumes to obtain the equilibrium lattice constant, bulk modulus and its pressure derivative as well as the stable magnetic structure. The calculated structural parameters of the materials are shown in Table 1.
Thermodynamic phase diagram and thermoelectric properties of LiMgZ (Z = P, As, Bi): ab initio method study
Published in Philosophical Magazine, 2021
Sajad Parsamehr, Arash Boochani, Maliheh Amiri, Shahram Solaymani, Elmira Sartipi, Sirvan Naderi, Amin Aminian
The half-Heusler ternary LiMgZ (Z = P, As, Bi) compositions are discussed using the first principles study in the density functional theory and FP-LAPW method to study thermoelectric behaviour, electronic structure and structural properties. The results confirm previous predictions of non-magnetic semiconductor behaviour for these compounds. To carry out this study, GGA approximation, spin-orbit interaction calculations (SOC), and BoltzTraP computational code are utilised. Structural studies and elastic constants as well as thermodynamic phase diagrams indicate that these three Heusler compositions are stable in the half-Heusler phase with F4-3 m symmetry which can be synthesised experimentally. These compounds are brittle with isotropic nature in elastic natures. The study of the thermoelectric behaviour of LiMgZ (Z = P, As, Bi) shows that the maximum value of the Seebeck coefficient at room temperature for LiMgP, LiMgAs and LiMgBi is about 2654, 2765, and 2854 µV/K, respectively. Hence, it can be said that these three half-Heusler compounds have p-type thermoelectric performance which are suitable for thermoelectric cooling applications. Their higher amount of ZT in lower temperatures indicated good thermoelectric efficiency in these for cooling applications.