A theoretical analysis of elastic and optical properties of half Heusler MCoSb (M=Ti, Zr and Hf)

Abstract

Ab initio calculation of the Elastic and Optical properties of cubic half-Heusler compounds MCoSb (M = Ti, Zr and Hf) are reported using the FP-LAPW approach of the Density Functional Theory. Generalized Gradient Approximation was used as the exchange and correlation potential for investigating these properties. It was found that the Bulk modulus decreases with the increase in temperature and increases with the increase in pressure for all of the three Heusler compounds under study. The Debye's temperature along with compressional, Shear and average elastic wave velocities has also been calculated. The elastic results are compared with the available theoretical and experimental works. The optical investigation of the compounds shows high reflectivity at the infrared region of the photon energy. The imaginary part of the dielectric function reveled the optically non-metallic behavior of the MCoSb compounds, with optical band gap being around 1 eV.

First-principles calculations to investigate mechanical, optoelectronic and thermoelectric properties of half-Heusler p-type semiconductor BaAgP

“…Therefore, BaAgP is a better candidate for photovoltaic material. The static refractive index, n(0) satisfies the relation n(0) 2 ≈ ε1(0), which verifies the accuracy of the calculation[68]. It is observed from the Fig.6(c) that beyond n(0), refractive index starts to increase up to ~2.10 eV and reaches a maximum value of 4.33 along a-axis and along c-axis this value is 3.70 at ~2.62 eV.…”

“…Fig.6(d)shows the photon energy (frequency) dependent extinction coefficient for BaAgP. It is observed that the trends of k(ω) is similar to that of ε2(ω) because it also provides a measure of absorption of incident radiation[68]. The maxima of extinction coefficient occurs at about 2.63 eV along a-axis and 3.18 eV along c-axis.…”

“…Generally, the half-metallic materials are used for spintronic device and semiconducting materials are used for solar cell and thermoelectric devices. The potentiality of a Heusler compound for a particular type of application can be easily determined by counting their valence electrons [5]. The HH materials with 18 valence electrons count (VEC) in the unit cell show thermoelectric properties.…”

“…The HH materials with 18 valence electrons count (VEC) in the unit cell show thermoelectric properties. Many members of this family such as ScRhTe [6] TiCoSb [5], ScPtSb [7], TiNiSn [8], LiMgN [9], ScNiGa [10], PdZrGe [11], RhTiSb [12], RhFeX (X=Sn, Ge) [13], TaCoSn [14], HfNiSn [15],…”

Pressure-Induced Enhanced Optical Absorption in Sulvanite Compound Cu3TaX4 (X = S, Se, and Te): An ab Initio Study

“…All other optical constants follow from the dielectric functions using standard equations. 29,39 The intraband transition contribution to the dielectric functions are inconspicuous, given the semiconducting nature of the compounds, and also the indirect interband transitions are neglected with comparison to direct interband transition, considering low photon momentum. The plot of the real part of the dielectric function with respect to the incident photon energy, at 0 and 10 GPa pressure, is shown in Figure 6 The optical conductivity plots shown in Figure 7(a)−(c) show a forbidden conduction region with energies corresponding to higher infrared and lower visible spectra, which further reconfirms the semiconducting nature of the compound.…”