Electronic and magnetic instability in Pr0.65Ca0.25Sr0.1MnO3

Electronic and magnetic instability in polycrystalline Pr0.65Ca0.25Sr0.1MnO3 manganite has been established from a systematic study of resistivity (ρ), magnetization (M) and specific heat (C). The sample shows a charge ordering transition at TCO∼200 K, an antiferromagnetic (AFM) ordering transition at TN∼175 K, a metal-insulator (MI) transition at TMI∼80 K and an unusual magnetic ordering transition at TM*∼45 K in the absence of magnetic fields. Though the C data do not show any anomaly at TMI for MI transition, these illustrate a much smaller anomaly than expected one at TM* and is suppressed by magnetic fields. This indicates that the unusual magnetic ordering in this sample is of canted, fluctuated or phase separation of AFM and ferromagnetic in nature which is established from the T-H phase diagram, as well as the thermal and magnetic hysteresis in ρ, M and C