Phase transitions in Nd1-xCaxMnO3 perovskites

Abstract A study is made of Nd 1− x Ca x MnO 3 perovskites by the dilatometry, IR spectroscopy and X-ray methods, and their magnetic and electrical properties are investigated. It is established that the removal of the cooperative Jahn-Teller distortions occurs via the first-order phase transition with a considerable reduction in the unit cell volume. No correlation between magnetic and electrical properties is found. The magnetic properties are interpreted in terms of the mechanism of superexchange interactions through anions.