<abstract xmlns="http://www.w3.org/1999/xhtml">In this paper, we have studied the electronic, elastic and thermoelectric properties of the half-Heusler LiCrZ (Z = C, N, Si, and P) materials in Type II phase, in this structure the atomic occupations are X (1/2,1/2,1/2), Y (0,0,0) and Z(1/4,1/4,1/4). The ferromagnetic state of Type II structure was found to be the most stable phase for all studied alloys. After calculating the elastic constants, we found out that the conditions of mechanical stability were verified only for LiCrSi and LiCrP alloys in Type II phase, at both equilibrium a0 and half metallic ahm lattice constants, which indicates that these two compounds can be synthesized experimentally. We should also mention that the half metallic behavior in Type II structure, for LiCrSi and LiCrP compounds, was obtained by straining the equilibrium lattice constants by 2% and 6%, respectively. At ahm, these two systems were identified to be true half metals due to their complete spin polarization and integer value of total magnetic moment. These last ones have reached 3μB per unit cell when Z = Si, and 4μB when Z = P. Using the mean field approximation (MFA), the Curie temperatures of Type II structure were also determined, where the values are estimated to be 456.2 K and 302.8 K, respectively. Finally, the thermoelectric performance has been explored by the classical Boltzmann theory. At low temperatures, the figure of merit has reached 0.73 and 0.93 for LiCrSi and LiCrP, respectively. The considerable ZT values and all calculated physical properties make these two systems promising candidates for thermoelectric applications.</abstract>

In this paper, we have studied the electronic, elastic and thermoelectric properties of the half-Heusler LiCrZ (Z = C, N, Si, and P) materials in Type II phase, in this structure the atomic occupations are X (1/2,1/2,1/2), Y (0,0,0) and Z(1/4,1/4,1/4). The ferromagnetic state of Type II structure was found to be the most stable phase for all studied alloys. After calculating the elastic constants, we found out that the conditions of mechanical stability were verified only for LiCrSi and LiCrP alloys in Type II phase, at both equilibrium a0 and half metallic ahm lattice constants, which indicates that these two compounds can be synthesized experimentally. We should also mention that the half metallic behavior in Type II structure, for LiCrSi and LiCrP compounds, was obtained by straining the equilibrium lattice constants by 2% and 6%, respectively. At ahm, these two systems were identified to be true half metals due to their complete spin polarization and integer value of total magnetic moment. These last ones have reached 3μB per unit cell when Z = Si, and 4μB when Z = P. Using the mean field approximation (MFA), the Curie temperatures of Type II structure were also determined, where the values are estimated to be 456.2 K and 302.8 K, respectively. Finally, the thermoelectric performance has been explored by the classical Boltzmann theory. At low temperatures, the figure of merit has reached 0.73 and 0.93 for LiCrSi and LiCrP, respectively. The considerable ZT values and all calculated physical properties make these two systems promising candidates for thermoelectric applications.

Electronic and Thermoelectric Properties of Li-Based Half-Heusler Alloys: A DFT Study

Condensed Matter and sustainable development Laboratory (LMCDD)

Annals of West University of Timisoara - Physics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

In this paper, we have studied the electronic, elastic and thermoelectric properties of the half-Heusler LiCrZ (Z = C, N, Si, and P) materials in Type II...

Electronic and Thermoelectric Properties of Li-Based Half-Heusler Alloys: A DFT Study

Publié en ligne: 16 déc. 2020

Pages: 95 - 107

Reçu: 27 juil. 2020

Accepté: 09 oct. 2020

DOI: https://doi.org/10.2478/awutp-2020-0006

Mots clés
Li-based half-Heusler compounds, DFT, elastic properties, Electrical conductivity

© 2020 F. Issaad et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Electronic and Thermoelectric Properties of Li-Based Half-Heusler Alloys: A DFT Study

Publié en ligne: 16 déc. 2020

Pages: 95 - 107

Reçu: 27 juil. 2020

Accepté: 09 oct. 2020

DOI: https://doi.org/10.2478/awutp-2020-0006

Mots clésLi-based half-Heusler compounds, DFT, elastic properties, Electrical conductivity

© 2020 F. Issaad et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Mots clés
Li-based half-Heusler compounds, DFT, elastic properties, Electrical conductivity