High pressure and doping effect on the magnetic properties of CaMn$_{2}$O$_{4}$

Polycrystalline Ca1-xSrxMn$_{2}$O$_{4}$ (x$=$0.05, 0.10, 0.15, and 0.20) compounds were synthesized using solid state reaction method. Samples were characterized by X-ray diffraction and magnetization measurements. The lattice constants (a, b, and c) determined by Rietveld refinement increases with Sr substitution. CaMn$_{2}$O$_{4}$ shows antiferromagnetic transition T$_{\mathrm{N}}$ near 220 K due to the Mn(III)-O-Mn(III) superexchange interaction. High-pressure effect on the T$_{\mathrm{N}}$ of CaMn2O4 has been investigated using piston-cylinder-type high-pressure apparatus designed for MPMS-XL7 magnetometer. It is found that the T$_{\mathrm{N}}$ increases with applying pressure up to 17.7 kbar at a rate of 0.487(22) K/kbar and decreases with higher Sr content.