Electrical-Transport, Magnetoresistance and Magnetic Properties of La1-xCaxMnO3 (x = 0.12 and 0.3) Single Crystals

Abstract

We report the electrical-transport and magnetic properties of the hole doped La0.7Ca0.3MnO3 (LCMO-1) and La0.88Ca0.12MnO3 (LCMO-2) single crystals, prepared using floating zone technique. The metal to insulator transition (TMI) occurs at 211 K along c-axis and TMI = 185 K along ab-plane for LCMO-1 single crystal. No electronic transition was observed over the whole temperature range under the magnetic field up to 8 T for LCMO-2 single crystal. It is observed that the TMI is higher along c-axis as compared to that in the ab-plane, consequently signifying more favorable hoping of electrons is along c-axis in LCMO-1. The ac-susceptibility measurement shows that ferromagnetic to paramagnetic transition temperature (TC) at 206 K for LCMO-1 and TC = 118 K for LCMO-2 single crystals which is seemingly related to notable change of resistance at 120 K in LCMO-2 single crystal. The maximum MR of 98% for LCMO-1 and 59% for LCMO-2 single crystals up to 8 T applied magnetic field along c-axis and ab-plane, respectively are observed.