Room temperature metal-insulator transition observed in Pb substituted lanthanum manganite

Abstract

Abstract Structural, magnetic and transport property of Pb substituted LaMnO 3 (La 1−x Pb X MnO 3 ; x=0.1, 0.2, 0.3, 0.4, 0.5) prepared by solid state reaction route have been studied systematically. X-ray diffraction,SEM, VSM,magneto-transport measurements were carried out on prepared samples. All the samples below x=0.4 composition were crystallized into single phase with R-3C space group of trigonal crystal class. The explored physical properties like magnetoresistance (MR), resistivity, metal–insulator transition temperature (T P ), magnetization (M s )and Curie temp. (T C ) varies with Pb concentration. Higher T P (298 K) and minimum resistivity was recorded for x=0.3 sample whereas no distinct peak corresponding to metal-insulator transition was observed for La 0.5 Pb 0.5 MnO 3 . Appreciable magnetoresistance (MR%) values were obtained for all the samples at 300 K.X-ray photoelectron spectroscopy (XPS) confirms the +2 oxidation state of Pb in all substituted samples. Fine tuning of T c could be achieved by varying Pb concentration in substituted LaMnO 3 samples, hence, it can find application in the field of cancer treatment i.e. Magnetic Hyperthermia.