Effect of hydrostatic pressure on the metal-insulator transition temperature of Pr0.7Ca0.3MnO3-based perovskites

We studied the hydrostatic pressure effect on the temperature dependence of resistivity of Pr0.7-xLaxCa0.3MnO3, Pr0.7Ca0.3-ySryMnO3 and Pr0.66Ca0.34-zSrzMnO3 compounds, with different metal-insulator transition temperatures T-M1. The pressure derivative dT(MI)/dP depends linearly on T-M1(-1). For the compounds Pr0.66Ca0.34-zSrzMnO3 it achieves a record value of 30 K/kbar. In contrast, the pressure effect on the charge ordering temperature is very weak. The analysis of changes in T-M1 and structural parameters at chemical and at external pressure shows that to achieve a qualitative agreement, a contribution of e-ph interactions and/or "Jahn-Teller" effects have to be taken into account. (C) 2002 Elsevier Science B.V. Ail rights reserved.