  We have investigated magnetization(M), magnetocaloric effect(MCE) and
magnetothermopower(MTEP) in polycrystalline Pr0.6Sr0.4MnO3, which shows a
second-order paramagnetic to ferromagnetic transition near room temperature (TC
= 305 K). However, field-cooled M(T) within the long range ferromagnetic state
shows an abrupt decrease at TS = 86 K for H < 3 T. The low temperature
transition is first-order in nature as suggested by the hysteresis in M(T) and
exothermic/endothermic peaks in differential thermal analysis for cooling and
warming cycles. The anomaly at TS is attributed to a structural transition from
orthorhombic to monoclinic phase. The magnetic entropy change is negative at TC
but changes to positive at TS. Thermopower (Q) is negative from 350 K to 20 K,
shows a rapid decrease at TC and a small cusp around TS in zero field. The MTEP
reaches a maximum value of 25% for deltaH = 3 T around TC which is much higher
than 15% dc magnetoresistance for the same field change. A linear relation
between MTEP and magnetoresistance, and between delta Sm and Delta Q are found
near TC. Further, ac magnetotransport in low dc magnetic fields (H less than or
equal to 1 kOe), critical analysis of the paramagnetic to ferromagnetic
transition and scaling behavior of the magnetic entropy change versus a reduced
temperature under different magnetic fields are also reported.
