Electron Doping and Enhanced Conductivity in Vacuum Annealed Sr2-xLaxIrO4
摘要
The lattice parameters, valence states of Ir ions, and electrical and magnetic properties of a series of Sr2-xLaxIrO4 polycrystalline samples have been systematically investigated with and without high temperature vacuum annealing. The annealing process leads to loss of oxygen content by ~ 1.86%. With annealing, partial Ir4+ ions are converted into Ir3+ state, reflecting the electron doping effect. A moderate enhancement of conductivity and a weakening of magnetism have been revealed, consistent with the decrease of energy gap due to vacuum annealing. These results could be insightful for further exploration of novel quantum phenomena in Sr2IrO4 system.