Thickness effect on electronic transport in single crystal La0.67Ca0.33MnO3 thin films

La0.67Ca0.33MnO3(LCMO) films were fabricated on (100) SrTiO3(STO) and (110) NdGaO3(NGO) substrates using facing-target sputtering technique. The resistivity rho and metal-to-semiconductor transition temperature T-MS were studied as functions of thickness. Although lattice stresses in LCMO/NGO and LCMO/STO are substantially different as confirmed by the XRD analyses, there is no direct correlation between structure and electronic transport in LCMO films, indicating the absence of strain effects on the transport properties, for example, rho, T-MS and activation energy E-a.