HALF HEUSLER PHONO DISPERSIO FULL

Partial phonon dispersion of Ni2MnGa in the fcc Heusler structure, along the G-K-X. Half-Heusler alloys have composition XYZ, whereas in the full-Heusler structure, the vacancies are filled in with a second atom (Y2-site), making the composition XY 2 Z. Heusler alloys are famous for localized large magnetic moments on Mn. They are also examined for the preservation of the integral magnetic moment against the lattice compression and expansion. (a) The crystal structure of half-Heusler and (b) full-Heusler alloys. They have also been explored regarding their thermodynamic properties using the quasi-harmonic approximation. The compounds have also been found to be dynamically stable against lattice vibrations on the basis of phonon dispersion calculations. The elastic properties show that the compounds are mechanically stable following Born stability criteria for cubic compounds and are found to be ductile in nature. Integral magnetic moment of 1.00 μ B is obtained for both the compounds which is in accordance with the Slater–Pauling Rule for half-Heusler alloys. To understand this phenomenon better, we systematically studied the halfmetallic nature, magnetism. Their only drawback is the remaining-high lattice thermal conductivity. The non-existence of imaginary frequencies in the phonon dispersion. Additionally, an ultrahigh average ZT of 0.93 between 300 and 973 K is achieved. The electronic properties in the form of spin-polarized band-structures and density of states of the compounds GeKCa and GeKSr show that they are half-metallic in nature with a finite and large half-metallic band-gap of 0.37 eV and 0.29 eV respectively in the spin-up states and a metallic behavior in the spin-down states with 100 % spin-polarization at the Fermi-level. Half-Heusler (HH) compounds are among the most promising thermoelectric (TE) materials for large-scale applications due to their superior properties such as high power factor, excellent mechanical and thermal reliability, and non-toxicity. rhodium-based half-Heusler alloys focusing on RhTiP, RhTiAs, RhTiSb, and RhTiBi. Among them, the p-type TaFeSb-based half-Heusler demonstrates a record high ZT of 1.52 at 973 K. Both the compounds GeKCa and GeKSr are found to be structurally stable in the ferromagnetic α-phase. They have long been known as magnetic materials, but can also be.

10 (a)), in which X and Y represent transition or rare-earth metals, and Z represents the main-group element, respectively.

HALF HEUSLER PHONO DISPERSIO FULL

The investigation is carried out using the spin-polarized calculations with pseudopotential approach using Generalized Gradient Approximation by Perdew–Burke–Ernzerhof (GGA-PBE). Heusler compounds are a class of ternary intermetallics, including full Heusler X 2 YZ with the L 2 1 structure, and half Heusler XYZ with C1 b structure (see the structural model shown in Fig. These are known as “inverse” Heuslers.This paper is based on the study of structural, electronic, magnetic, elastic, phonon dynamics and thermodynamic properties of d 0 half-Heusler alloys GeKZ (Z = Ca, Sr) using the Density Functional Theory (DFT) approach. A third Heusler family with formula unit A 2BC (similar to the “full”-Heuslers) consists of alloys that can be viewed as “AB” layers alternating with “AC” layers as shown in Figure 1c. phonon dispersion and electronic band structure calculations. 118.71 u.a.m.), we observe a drastic L reduction with increased Sn concentration. Half-Heusler (HH) alloys with an 18 valence electron count have attracted significant. Despite the small contrast of mass between Sb and Sn (121.76 vs. These are known as “half”-Heuslers or semi-Heuslers. Herein, to identify the major phonon-scattering mechanisms in half-Heusler compounds, we start from synthesizing ZrCoSb-based half-Heusler compounds with partial substitution of Sn at the Sb sites. A related Heusler family has members with formula unit ABC in which half of the “A” atoms of the full-Heusler are replaced by vacancies as shown in Figure 1b. The band gap, lattice constant and other structural and electronic property results obtained in this work compare well with experimental and theoretical results from previous work. Thus members of this Heusler family with formula unit A 2BC (known as “full”-Heuslers) can be viewed as layers consisting of a square lattice of “A” atoms alternating with layers of “B” and “C” atoms as shown in Figure 1a. The other half would be the gear that screws to this. The structure of the alloys was later found to be fcc with a 4 atom basis consisting of a single formula unit. The other half would be the gear that screws to this. These alloys were interesting because some of them were ferromagnetic even though their constituent atoms were non-ferromagnetic as elements. Heusler alloys are named for the German mining engineer and chemist Friedrich Heusler who investigated Cu-Mn-Al alloys around 1900.

Half heusler phono dispersio