Electronic structure and magnetic properties of diluted magnetic semiconductor K and Mn co-doped BaCd_2As_2 from first-principles calculations

摘要

In this paper, we have investigated the electronic structure and magnetic properties of K and Mn co-doped BaCd_2As_2 using density functional theory within the generalized gradient approximation (GGA) + U schemes. Calculations show that the ground state magnetic structure of Mn-doped BaCd_2As_2 is antiferromagnetic while K and Mn codoped BaCd_2As_2 is ferromagnetic. Electronic structures indicate that the superexchange mechanism leads to the antiferromagnetic coupling between Mn atoms in Mn-doped BaCd_2As_2 while the hole-mediated Zener's p-d exchange mechanism leads to the ferromagnetic coupling between Mn atoms in K and Mn co-doped BaCd_2As_2.