Ab initio and Mössbauer study of the electronic structure and the hyperfine parameters of ZnFe2O4 systems

J. J. MELO QUINTERO; K. L. SALCEDO RODRÍGUEZ; G. A. PASQUEVICH; P. MENDOZA ZELIS; S. STEWART; C. E. RODRÍGUES TORRES; L. A: ERRICO

Hamburgo

Conferencia; International Conference on Applications of Mössbauer Effects, ICAME 2015; 2015

We present here a combined Mössbauer and ab initio study of the hyperfine properties of ZnFe2O4 ferrite (ZFO). Zinc ferrite powders were thermally treated at different temperatures in a range between 100 to 850 ºC under low oxygen pressure atmosphere to investigate the influence of oxygen vacancies in the ferromagnetism observed in Zn-ferrites. In the theoretical study we considered different defects (oxygen vacancies, cation inversion) in order to determine their effect on the hyperfine parameters, magnetic moments and the magnetic alignment of ZFO. The comparison theory-experiments enables us to characterize the local structure around Fe atoms and to identify the hyperfine interactions observed. Our results shows the presence of cation inversion in the samples treated at temperatures below 330ºC and vacancies formation for treatments performed at high temperatures (400ºC to 600ªC) .