Investigations on exchange interactions and Curie temperatures of Zr2CoZ compounds by using first-principles and Monte Carlo calculations

Abstract

Abstract We systematically study the electronic and magnetic properties of Zr2CoZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb) compounds by using the first-principle calculations, and further focus on exploring their exchange interactions and Curie temperatures. Results exhibit that Zr2CoGa, Zr2CoIn and Zr2CoTl compounds show a high spin polarization. Moreover, the Heisenberg calculations imply that the Zr(A)-Zr(B), Zr(A)-Zr(A) and Zr(A)-Co(C) exchanges in interactions significantly affect the Curie temperature. In contrast, the Zr(B)-Zr(B), Zr(B)-Co(C) and Co(C)-Co(C) exchanges almost are limited to 15 meV in all cases. Based on these calculated exchange coupling parameters, Curie temperatures are evaluated by adopting the mean field approximation and Monte Carlo simulation, it is found that the Curie temperatures of Zr2CoZ (Z = Al, Ga, In, Tl, Sn, Pb) are noticeably higher than room temperature, indicating that they are promising candidates for spintronics applications.