Hydrostatic pressure effects on the electrical transport properties of Pr0.5Sr0.5MnO3

We studied single-crystalline Pr0.5Sr0.5MnO3 by means of measurements of magnetic susceptibility and specific heat at ambient pressure (P) and electrical resistivity (rho) in hydrostatic pressures up to 2 GPa. This material displays ferromagnetic (FM) order, with Curie temperature T-C approximate to 255 K. A crystallographic transformation from I4/mcm to Fmmm is accompanied by the onset of antiferromagnetism (AFM), with Neel temperature T-N approximate to 161 K. The effect of pressure is to lower T-C and to raise T-N at the approximate rates of -3.2, and 14.2 K/GPa, respectively. Although the value of T-N increases with P, due to the enhancement of the superexchange interactions, the AFM-Fmmm state is progressively suppressed, as pressure stabilizes the FM-I4/mcm phase to lower temperatures. The rho vs T data suggest that the AFM phase should be completely suppressed near 2.4 GPa.