Structural and Electrical Properties of CaMnO3 Prepared by Sol-Gel Method25

The structural and electrical properties of CaMnO3 prepared by a sol-gel technique using citric acid as a chelating agent at 8000C were studied; the phase formation was determined by powderXRD. The surface morphological studies were carried out through SEM and EDX confirmed the chemical compositions of the sample. The various modes of vibrations due to the Mn-O and O-Mn-O stretching bonds were observed by FTIR spectroscopy studies.The electrical properties of the prepared samples were analysed at different temperatures in the frequency ranges from 50Hz to 5MHz. Introduction. The Manganese oxide based elements with the low-temperature synthesis of ABO3 perovskite type oxides has attracted due to their interesting technological applications in thermoelectric, magnetic and electrical properties have drawn more attention from the past few decades [1]. These compounds show large magnetoresistance properties due to an unusual spin – orbital and charge ordering phenomenon these can be easily altered by temperature, pressure, applied field, doping and also the way of preparation. The manganese based on CaMnO3 compound has a mixed valence system of Mn3+/Mn4+ could induce charge transfer effects and double-exchange interaction it possesses many applications such as solid fuel cells, magnetoresistance switchings, cathode materials and oxygen sensors [2]. The perovskite structure of CaMnO3 is a G-type antiferromagnetic insulator with an additional weak ferromagnetic component in ground state and it belongs to an orthorhombic structure this kind of structure is quite suitable for colossal magnetoresistance, the strong correlation between an electronic system and thermoelectric materials [3]. Recently, CaMnO3 has been one of typical perovskite oxide which shows an excellent dielectric polarisation behaviour being one kind of absorbing agent and a promising thermoelectric material with high Seebeck coefficient low electrical conductivity [4]. CaMnO3 has synthesiszed with various methods namely hydrothermal method, solid state reaction, sol-gel method and so on. To obtain a homogenous compound, uniform particle size, high crystallinity and morphology, the sol-gel method is used to reduce the agglomeration in the prepared compound. Most of the studies of CaMnO3 have focused mainly on the magnetic and thermal properties; less attention has been paid about structural and electrical properties of the materials. Here in our report the results of structural, morphological, dielectric and impedance studies on CaMnO3. The electrical properties for the synthesised CaMnO3 as a function of frequency varying from 50 Hz to 5 MHz at different temperatures have measured. Experimental. The perovskite CaMnO3 have synthesized the material by sol-gel method using citric acid as chelating agent. The stoichiometric ratio of Calcium nitrate (Ca (NO3)3.4H2O) and Manganese nitrate (Mn (NO3)3.4H2O), dissolved in the deionized water to form a homogenous solution and citric acid (C6H8O7) solution was added slowly drop by drop to the homogenous solution. All reagents used 25 © 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/