Colossal thermoelectric power in Gd-Sr manganites

摘要: Manganites belonging to the series Gd1−xSrxMnO3 (x=0.3, 0.4 and 0.5) were prepared by wet solid-state reaction their thermoelectric power was evaluated. Thermoelectric measurements revealed a peak value at ~40 K. All samples exhibited colossal thermopower ~40 K in that Gd0.5Sr0.5MnO3 maximum of ~35 mV/K, which is largest reported for these class materials this temperature. Temperature-dependent magnetisation showed exhibit phase transition from paramagnetic spin-glass–like state temperatures. Plausible mechanisms responsible observed Gd-Sr manganites are discussed.