Structural, electronic, and magnetic properties of quaternary Heusler CrZrCoZ compounds: A first-principles study**Project supported by the National Natural Science Foundation of China (Grant No. 11864021) and Foundation of A Hundred Youth Talents Training Program of Lanzhou Jiaotong University, China, the Key Talent Foundation of Gansu Province, China (Grant No. 2020RCXM100), and Excellent Research Team of Lanzhou Jiaotong University, China (Grant

Abstract

Using the first-principles calculations, we study the structural, electronic, and magnetic properties along with exchange interactions and Curie temperatures for CrZrCoZ (Z = Al, Ga, In, Tl, Si, Pb) quaternary Heusler alloys. The results show that the CrZrCoZ alloys are half-metallic ferrimagnets, and their total spin magnetic moments, which are mainly carried by the Cr atom, obey the Slater–Pauling rule. Analysis of local density of states confirms that the exchange splitting between eg and t2g states leads to the formation of half-metallic gap. According to the calculated Heisenberg exchange coupling parameters, it is found that the Cr(A)–Cr(A) and Cr(A)–Zr(B) exchanges dominate the appearance of ferrimagnetic states in CrZrCoZ (Z = Al, Ga, In, Tl, Pb) alloys, and it is the Cr(A)–Zr(B) and Zr(B)–Zr(B) exchanges for CrZrCoSi alloy. Finally, we estimate the Curie temperatures of CrZrCoZ by using mean-field approximation, it is found that the CrZrCoZ (Z = Al, Ga, In, Tl, Pb) alloys have noticeably higher Curie temperatures than room temperature. So, we expect that the CrZrCoZ alloys are promising candidates in spintronic applications in future.