Coexistence of colossal magnetoresistance, a Griffiths-like phase, and a ferromagnetic insulating ground state in single crystal La_(0.73)Ba_(0.27)MnO_3

摘要

Detailed temperature/field-dependent magnetic and transport behaviors are reported for a nominally doped La_(0.73)Ba_(0.27)MnO_3 single crystal. The magnetic analysis demonstrates an intriguing coincidence of critical exponents consistent with Heisenberg model values (γ=1.39, β=0.38,δ =4.83) and the presence of a Griffiths-like phase. The transport measurements yield a ferromagnetic insulating ground phase, but one complemented by the appearance of colossal magnetoresistance near the ferromagnetic to paramagnetic (FM-PM) phase transition temperature T_C=245 K.