Structural and electronic structure investigations across low temperature magnetic transitions in CaMn7O12: A EXAFS study

Abstract

The CaMn7O12 which so far has remained on top among type-ii multiferroic materials exhibiting unconventional ferroelectricity shows intriguing magnetic transitions at low temperatures, and local geometrical investigations around those temperatures are scarce. Temperature dependent Mn K-edge x-ray absorption spectroscopy has been used to gain insights about the local geometrical and electronic structure near the magnetic transition temperatures. X-ray absorption near edge spectra below 25 K indicates a considerable change in electronic structure in CaMn7O12, which is accompanied with more ordered local structure around Mn atoms.