Magnetic resonance spectrum of a two-phase state in single crystals of La0.7Pb0.3MnO3 lanthanum manganite

Two absorption lines are observed over a wide temperature range below T-c i n the magnetic resonance spectrum of an La0.7Pb0.3MnO3 single crystal. Thes e lines correspond to two magnetic phases in the sample. The frequency-fiel d dependence of spectra obtained in the range of microwave radiation freque ncies 10-77 GHz allows these phases to be interpreted as ferromagnetic and paramagnetic phases. The phase volume ratio depends on the temperature and the magnitude of the external magnetic field. Features in the temperature b ehavior of parameters of the magnetic absorption line are observed in the r egion of the highest magnetic resistance of the sample. The results are int erpreted within the mechanism of electronic phase separation. (C) 2000 MAIK "Nauka/Interperiodica".