Magnetic Field and Pressure Effects on the Electrical Resistivity of Single Crystal Pr2/3(Ca,Pb)1/3MnO3

The effects of magnetic field (H) and pressure (P) on the temperature (T) dependence of electrical resistivity (ρ) are reported for a new manganese-containing compound, Pr2/3(Ca,Pb)1/3MnO3, which was grown in single-crystal form by a flux method. The material was found to order magnetically with applied-field strength below 175 K, but have zero remanence (MR) as H→O, i.e., there was no spontaneous magnetization (MS), only field-induced magnetization (Mi). A zero-field “insulator” to metal transition occurred at 146 K and this transition temperature (T1M) was found to increase with increasing field strength. The change in resistivity with field, ρO-ρH, normalized with respect to ρH, was 900% at 146 K and H = 5T. On application of hydrostatic pressure the zero-field resistivity decreased by 200%/GPa above room temperature. The electrical transport observed was consistent with a thermally-activated process, and this process was found to be relatively independent of pressure (0–4 GPa) in the temperature region (300 K–400 K) studied.