Pursuing insulator-to-metal transition in Sr2Ir1-xMxO4 (M=Li, Zn, Sc) solid solutions

Three series of Sr2Ir1-xMxO4 (M = Li, Zn, Sc) samples have been synthesized via solid state reaction technique. The influences of Ir site doping by elements with different valence states (e.g., monovalent Li+, divalent Zn2+, and trivalent Sc3+) in Sr2IrO4 are investigated through a comparative study on the lattice parameters, the transport and magnetic properties of the Sr2Ir1-xMxO4 samples. The insulator-to-metal transition has been successfully realized in Li and Zn doped samples, while the Sc doped samples exhibit persistent insulating behavior. The occurrence of insulator-to-metal transition is ascribed to the introduction of sufficient amount of charge carriers in Li and Zn doped samples.