Magnetic field induced evolution of highly resistant Griffiths phase in fine grain manganite La0.75Ca0.25MnO3

The Griffiths phase in fine grain manganite La0.75Ca0.25MnO3 is studied by the complementary structural methods, DC magnetic susceptibility and ESR spectroscopy. The Griffiths like phase is detected above Curie temperature between 232 and 280 K and sustains up to high magnetic field of 3000 Oe. The magnetic susceptibility of Griffiths phase is a decreasing function of temperature. The magnetic field dependence of Griffiths phase susceptibility reveals its remarkable contribution to measured total susceptibility. The additional anomalous ESR signal supperimpossed on the paramagnetic one is ascribed to the locally inhomogeneous Griffiths like phase in agreement with the core - shell model.