Specific heat studies on the charge and magnetic ordering in manganites

Abstract

Specific heat ( C) studies with a wide range of temperatures ( T=80– 300 K ) on polycrystalline manganites Pr 1− x Ca x MnO 3 (113-PCMO) with x=0.3–0.4, La 1− y Ca y MnO 3 (113-LCMO) with y=0.3 and 0.5, and La 2−2 z Sr 1+2 z Mn 2O 7 (327-LSMO) with z=0.3 and 0.5 are reported. Clear anomalies in C are identified which are associated with charge ordering (CO), antiferromagnetic (AFM) and ferromagnetic (FM) transitions. The anomalies in 113-PCMO and 113-LSMO are bigger than those of 327-LSMO. The possible explanations are discussed on the basis of dimensionality effects.