Effect of Pressure on the Magnetoresistance of Single Crystal Nd0.50.36Pb0.14MnO₃-δ

To investigate the observed huge variations in magnetoresistance between different samples of manganite perovskites we have performed the first high-pressure measurement of magnetoresistance in single crystal Nd0.5Sr0.360.14MnO₃-δ. Both resistivity and magnetoresistance are strongly suppressed upon application of pressure. The decrease in magnetoresistance with increasing pressure rules out substrate-induced compressive strain as a source of enhanced magnetoresistance. Instead, the magnetoresistance differences between samples are ascribed primarily to the more abrupt nature of the semiconductorlike to metallic phase transition at lower temperatures.