Comparative Study on Multifunctional Behaviors of La<sub>0.7</sub>Ca<sub>0.3</sub>MnO<sub>3</sub> and La<sub>0.7</sub>Ca<sub>0.24</sub>Sr<sub>0.06</sub>MnO<sub>3</sub> Single Crystals

Abstract

We report the electrical-transport, magneto-transport, and magnetic properties of the hole doped La0.7Ca0.3MnO3 (LCMO) and La0.7Ca0.24Sr0.06MnO3 (LCSMO) single crystals, prepared using floating zone technique. The resistivity data shows the metal to insulator transition (TMI) occurs at 211 K and 290 K for LCMO and LCSMO single crystals respectively. The electrical transport mechanisms of these crystals are investigated by using different theoretical models, for temperatures below and above TMI. The magnetization measurements show that these single crystals exhibit ferromagnetic to paramagnetic transition temperature (TC) at 208 K for LCMO and 273 K for LCSMO single crystals. From device application point of view, both samples show the maximum MR of 98% for LCMO and 80% for LCSMO at 8 T applied magnetic field, while for bolometer IR detectors application point of view the temperature coefficient of resistance (TCR) are found to ~17% K-1 and 28% K-1 for LCMO and LCSMO respectively.