Mössbauer spectroscopy study of a new layered iron oxyselenide Na2Fe2Se2O

We report the results of 57Fe Mössbauer spectroscopy study, complemented by first-principles energy-band structure and the hyperfine-interaction parameters calculations, of a recently discovered layered iron oxyselenide Na2Fe2Se2O. It is confirmed that Na2Fe2Se2O is a Mott insulator. It is demonstrated experimentally that Na2Fe2Se2O orders antiferromagnetically with the Néel temperature TN=74.8(2) K and with the Fe magnetic moment of 3.0(1) μB. The calculated hyperfine-interaction parameters are in good agreement with the corresponding experimental parameters. The Debye temperature of Na2Fe2Se2O is found to be 274(3) K.