Abstract
A-site-ordered quadruple perovskite CeMn7O12 – the first ternary oxide in the Ce–Mn–O system – was synthesized at high pressure of 6 GPa and high temperature of about 1670 K, and its structural, magnetic, and dielectric properties were investigated. CeMn7O12 crystallizes in space group Im-3 above 649 K, and in space group I2/m below 649 K. No other structural phase transitions were found down to 10 K. Crystal structures were investigated using synchrotron X-ray powder diffraction (a = 7.50069 Å, b = 7.36836 Å, c = 7.49086 Å, β = 91.2125° at 295 K and a = 7.47367 Å at 700 K), and the structural parameters (Ce–O bond lengths) suggest the Ce3+ oxidation state giving the charge distribution as Ce3+Mn3+7O12. CeMn7O12 shows one long-range-ordered ferrimagnetic transition at TN = 78 K accompanied by very weak kink-like dielectric anomalies. Strong dielectric relaxation due to extrinsic processes was observed near 18–35 K.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
