Zinc doping effects on the structure, transport and magnetic properties of La0.7Sr0.3Mn1-xZnxO3 manganite oxide

Abstract

The processing, microstructures and properties of La0.7Sr0.3Mn1–xZnxO3 perovskite manganite, with x= 0; 0.1, 0.2, and 0.3 have been investigated. X-ray diffraction, scanning electron microscopy (SEM) and other characterisation methods were used to study the relations of microstructure and properties. The X-ray powder diffraction results show a single phase for the 0 < x < 0.3 region that confirms the zinc incorporation into the Mn site. The SEM images with magnification 1500 × indicate that the studied system is a singlephase. The transport measurements show decreasing of insulator to metal transition temperature, Tt; with increasing the zinc concentration on the Mn site, while the resistivity increases with increasing the zinc doping level for 0 < x < 0.1: The maximum resistivities are found at 380 and 160 K, respectively.The PPMS measurements show that the magnetisation value is greatest for x = 0.1 and drastically decrease for theparent material, as well as with increasing the zinc doping concentration above 20%, when the compound changes from ferromagnetic to paramagnetic. The paramagnetic to ferromagnetic transition temperature variations, Tc; agrees with the insulator to metal variations, Tt; from the transport measurements for the parent and 10% doped material. For zinc doping levels above 20%, the behavior of the studied system changes from ferromagnetic to paramagnetic.© 2003 Elsevier Science Ltd. All rights reserved.