Publication Date:
2016-10-13
Description:
Magnetite (Fe 3 O 4 ) was doped with radioactive 111m Cd and 111 In ions as impurities, and their residence sites and thermal stability were investigated by means of time-differential perturbed angular correlation (TDPAC) spectroscopy. Well-defined TDPAC spectra unequivocally show their sites: Cd ions are stably located only in the tetrahedral A site in all the temperature range of the present observation (77 K–873 K); In ions also specifically occupy the A site at low temperature, but at high temperature part of them select the B site in a reversible fashion. The energy difference between the A and B sites for the accommodation of In was experimentally determined to be 0.119 (9) eV by assuming a Boltzmann distribution for the populations of the 111 In probe in the respective sites. The element-dependent thermal stabilities observed for Cd and In were well corroborated by density functional theory calculations. The successful observation of thermally activated site-to-site displacement of impurity In ions in Fe 3 O 4 is reported.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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