Gd-doping-induced insulator-metal transition in SrTiO3

Recently, insulator-metal transition was found experimentally in Gd-doped SrTiO3 films. Here, we present first-principle investigation on the structural, electronic and magnetic properties of Sr1−xGdxTiO3 within density-function theory. The spin-polarized calculations give a diamagnetic insulator at x=0, a ferrimagnetic metal 0.125≤ x≤0.5 and a ferrimagnetic insulator x=1 and all Ti ions moments are antiparallel to Gd ions moments. Magnetic Gd-doping distorts the structures of Sr1−xGdxTiO3 films and results in ferrimagnetism. Doped electrons occupy the bottom of conduction bands so that insulator-metal transition occurs. These calculated results are in agreement with available experiments.