Pressure-Induced Superconductivity from Doping-Induced Antiferromagnetic Phase of 112-type Ca_1−xLa_xFeAs₂

Abstract

The effects of pressure on antiferromagnetic (AFM) and superconducting phase\ntransitions of 112-type Ca$_{1-x}$La$_{x}$FeAs$_{2}$ were studied, and the\nin-plane electrical resistivity $\\rho_{ab}$ was measured with an indenter-type\npressure cell. The AFM phase transition temperatures of $T_{\\rm N}$ = 47, 63,\nand 63 K at ambient pressure for $x$ = 0.18, 0.21, and 0.26 was suppressed by\napplying pressure $P$, with superconductivity emerging at critical pressures of\n$P_{\\rm c}$ $\\simeq$ 0, 1.5, and 3.4 GPa, respectively. Correspondingly, the\nslope of $T_{\\rm N}$ against $P$ decreased as $dT_{\\rm N}/P$ $\\simeq$ $-$15 and\n$-$2 K/GPa for $x$ = 0.21 and 0.26, respectively. Thus, although the AFM phase\nwas stabilized with La doping $x$, the AFM phase was suppressed by pressure,\nand superconductivity eventually emerged.\n