ESR studies on GMR related materials: II. ESR of Mn in La0.97Ca0.03MnO3

摘要

ESR measurements have been carried out for Lao(0.97)Ca(0.03)MnO(3) at temperatures from 4 K up to 760 K. below similar or equal to 243 K, two kinds of spectra, the high-field and low-field signals, are observed down to 96 and 4 K, respectively. They are assumed to be due to Mn4+ and Mn3+ ions, respectively From the g-shifts of the high-field (Mn4+) signals, the magnetic interaction coefficient between Mn4+ and Mn3+ spins is estimated. Clear single ESR was observed above similar or equal to 255 K, and its linewidth and intensity are obtained as a function of temperature. The linewidth nearly follows exp(-550/T), and the intensity gradually deviates from Curie's law below similar or equal to 550 K, presumably due to the spin-cluster formation. [References: 5]