First-principles investigation of Cr doping effects on the structural, magnetic and electronic properties in

We have investigated the structural, magnetic, and electronic properties of SrRu 1 − x Cr x O 3 , using first-principles density functional theory within the generalized gradient approximation (GGA) + U schemes. The entire series of SrRu 1 − x Cr x O 3 ( x = 0 , 0.125, 0.25, 0.5) are stabilized in the perovskite structure which are in agreement with experimental findings. Our spin-polarized calculations give a half-metallic ground state for SrRuO 3 and a metallic ground state for x ⩽ 0.25 regime. An insulator ground state has been found for x > 0.25 regime. The magnetic structures for x ⩽ 0.125 are found to be the ferromagnetic state while the magnetic structure for x = 0.25 is the ferrimagnetic state where any Cr ion is coupled antiparallel to the Ru at the near sites. The magnetic structure for x = 0.5 is found to be the antiferromagnetic state. Low Cr-doped material ( x < 0.25 ) involves the Cr 3 + in the ferromagnetic ordering and enhances the ordering temperature. With increasing x , the substitution of itinerant Ru ions by localized Cr ions enhances the p–d coupling between O and transition metal. It also strongly drives the system from the ferromagnetic metal to the antiferromagnetic insulator.