An abnormal effect of low level Cu doping on the magnetism and conductivity of La0.7Ca0.3MnO3-delta

作者：Tovstolytkin AI^*; Pogorilyi AN; Shypil EV; Podyalovski DI

来源：Physics of Metals and Metallography, 2001, 91: S214-S218.

A strong suppression of metallic-like ferromagnetism caused by the partial substitution of Cu for Mn has been found in well-characterized (X-ray diffraction, X-ray fluorescence, EPR) oxygen-deficient polycrystalline samples of the La0.7Ca0.3Mn1-xCuxO3-delta system. A sharp drop (> 80 K) in both metal-insulator, T-p, and magnetic, T-C, transition temperatures is observed at low levels of Cu doping (0 < x < 0.04), which is accompanied by a drastic modification of the electron paramagnetic resonance (EPR) properties. The results obtained are discussed in terms of an interplay between double exchange and charge ordering, a tendency towards the latter being enhanced by both the presence of Cu impurities in the Mn sublattice and the oxygen deficiency of the samples.

• 出版日期2001