Structural, electronic, and magnetic properties of quaternary Heusler CrZrCoZ compounds: A first-principles study

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 e_g and t_2g 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.