Pressure effect on magnetism in phase-separated Cr-doped Pr_0.5Ca_0.5Mn_1-xCr_xO₃ manganites

Magnetic properties of Pr_0.5Ca_0.5Mn_1-xCr_xO₃ (0.015≤x≤0.5) samples were investigated under pressures up to 11 kbar. For x=0.015 and 0.03 samples, an applied pressure enhances significantly the Curie temperature (dT_C/dP∼2 K/kbar), enhances the ferromagnetic phase volume below T_C, and narrows appreciably the hysteresis in the vicinity of T_C. For x=0.2 and 0.5 samples, pressure does not affect practically the magnetic transition temperature, but reduces noticeably the magnetization in a wide temperature range. Observed phenomena for x=0.015 and 0.03 samples are related to the interfacial elastic energy at the interface of different magnetic phases and to the suppression of the Jahn-Teller distortions under pressure. For higher doped samples, pressure possibly increases antiferromagnetic interactions between Cr³⁺ and Mn⁴⁺ ions.