Phase Transitions in CuAs-based K$_{x}$Sr$_{1-x}$Cu$_{4}$As$_{2}$ System

Inspired by the superconductivity with a T$_{c }\sim $ 3.5 K reported by Han et al. in Cu-based LiCu$_{2}$P$_{2}$, the Cu-based compound SrCu$_{4}$As$_{2, }$which has a more complex CuAs layers structure sandwiched by Sr layers, was synthesized and characterized. The magnetoresistance measurements show two anomalies around $\sim $140K and $\sim $60K, respectively, which is also consistent with the results of specific heat measurement. Systematically studies of K-doping into SrCu$_{4}$As$_{2}$ system are carefully investigated at ambient and high pressures and no superconductivity has been found in the K$_{x}$Sr$_{1-x}$Cu$_{4}$As$_{2}$ system down to 2K, although superconductivity might occur at lower temperature in this system. The overall pressure and doping effects on the magnetic and transport properties of the compounds will be presented and discussed.