Hole doping induced metal-insulator transition in Sr$_{1-x}$K$_x$IrO$_4$

We report a metal-insulator transition against temperature in hole doped Sr2IrO4. The temperature dependence of \textit{ab}-plane resistivity of the doped Sr2IrO4 shows a peak at 6.5K. The magnetization against temperature shows a magnetic transition temperature about 200 K that is significantly reduced compared with its pristine material (240K). Hall effect measurements confirm that the conduction carrier is hole. A small magnetoresistance $\sim$ 3.5{\%} with significant anisotropy with respect to magnetic field orientation is observed, indicating the importance of spin-orbital coupling on conduction mechanism of the materials.