Drastic improvement of Curie temperature by chemical pressure in N-type diluted magnetic semiconductor Ba(Zn,Co) $$_{2}$$ 2 As $$_{2}$$ 2

Abstract

Abstract We report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn $$_{1-x}$$ 1 - x Co $$_{x}$$ x ) $$_{2}$$ 2 As $$_{2}$$ 2 which has a maximum $$T_C$$ T C $$\sim$$ ∼ 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by $$\sim$$ ∼ 0.3 $$\%$$ % with 15 $$\%$$ % Sr doping, but drastically increase the ferromagnetic transition temperature by 18 $$\%$$ % to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As $$_{4}$$ 4 tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co) $$_{2}$$ 2 As $$_{2}$$ 2 DMS.