Strain Effect in Cation Disorder Manganite Films

Y and Sr co-doped La2/3Ca1/3MnO3 films with different A-site cation disorder were deposited on Yttrium-stabilized ZrO2 (YSZ) single crystal substrate by modified off-axis rf magnetron sputtering technology. The influences of A-site cation disorder and biaxial strain on the surface morphologies and transport properties are discussed in detail. At high temperature, the mechanism of conduction is changed from the small polaron hopping model to the variable-range hopping model with increasing cation disorder, which reveals that cation disorder induces carrier localization. The Curie temperature and the magnetoresistance decrease with the increase of cation disorder. It reveals the variation of phase separation to be caused by the increasing cation disorder which suppresses the long-range FM metal state.