Effects of phosphorus doping on the physical properties of axion insulator candidate EuIn₂As₂

Abstract We report an investigation on the single crystal growth, magnetic and transport properties of EuIn$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ (0$\leqslant$ x $\leqslant$1). The physical properties of axion insulator candidate EuIn$_{2}$As$_{2}$ can be effectively tuned by P-doping. With increasing $x$, the $c$-axis lattice parameter decreases linearly, the magnetic transition temperature gradually increases and ferromagnetic interactions are enhanced. This is similar as the previously reported high pressure effect on EuIn$_2$As$_2$. For $x=0.40$, a spin glass state at $T_g=10~$K emerges together with the observations of a butter-fly shaped magnetic hysteresis and slow magnetic behavior. Besides, magnetic transition has great influence on the charge carriers in this system and negative colossal magnetoresistance is observed for all P-doped samples. Our findings suggest that EuIn$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ is a promising material playground for exploring novel topological states.