Two step solid state synthesis and Synchrotron X-ray characterizations of ceramic Co3TeO6; an improper multiferroic

A two step solid state reaction route has been presented to synthesize monophasic cobalt tellurate (Co3TeO6, CTO) using Co3O4 and TeO2 as starting reagents. During synthesis, initial ingredient Co3O4 is found better than CoO in circumventing the intermediate Co5TeO8 or CoTeO3 phases. High resolution Synchrotron X-ray Diffraction has been used to probe different phases present in synthesized CTO and to achieve its single phase. Further, XANES studies near Co K and Te L-edge reveal mixed oxidation states of Co (i.e. Co2+ and Co3+) and +VI valence state of Te respectively, which is also confirmed with XPS. Charge imbalance due to different oxidation states of the Co-ions has been observed to be compensated by plausible Te-cations vacancy. Enhanced multiferroic properties like effective magnetic moment (JAP 116, (2014)) have been correlated with the present synthesis route.