The influence of Mn-doping types on electronic structure and dilute magnetic property of Ca2Ge

Abstract

The dilute magnetic semiconductor (DMS) materials have important application prospects in the field of electronic science and technology. Ca2Ge is a new environmentally friendly semiconductor material. The structure characteristics indicate that the dilute magnetic properties can be achieved by doping, in the theory. There are CI, CII, CIII, OI, OII and OIII six doped types by Mn doping. For the CI, CII and OIII, Ca2Ge is a semiconductor with a band gap of 0.21 eV, 0.21 eV and 0.065 eV, respectively; For the OII, Ca2Ge turns into a semi-metallic; For the CIII and OI, Ca2Ge turns into a metal. Ca2Ge trans into ferromagnetism with Mn doped, the molecular magnetic moments of CI, CII, CIII, OI, OII and OIII are 5 μB, 5 μB, 1 μB, 5 μB, 5 μB and 7 μB, respectively. The results of the projected density of states (PDOS) indicated that the magnetism mainly comes from the Mn 3d orbital spin, the orbital population shows that the spin of Mn atom affects the spin of Ca atom and the spin of Ge atom, the magnetic moment that is excited by Mn atom doping.