Artigo
Insight into the Effects of Fe Addition on the Local Structure and Electronic Properties of SrTiO3
Registro en:
Journal Of Physical Chemistry C. Washington: Amer Chemical Soc, v. 118, n. 9, p. 4930-4940, 2014.
1932-7447
10.1021/jp408839q
WOS:000332756000040
Autor
Silva, Luis F. da
M'Peko, Jean-Claude
Andres, Juan
Beltran, Armando
Gracia, Lourdes
Bernardi, Maria I. B.
Mesquita, Alexandre [UNESP]
Antonelli, Eduardo
Moreira, Mario L.
Mastelaro, Valmor R.
Resumen
This paper reports an experimental and theoretical investigation of the effects of adding Fe to the perovskite strontium titanate SrTiO3. The effects include changes in the short-order range structure as well as in the electronic and electrical properties. X-ray diffraction analysis reveals that the SrTi1-xFexO3 network shrinks with increasing Fe content, while X-ray absorption spectroscopy measurements of the Ti and Fe K-edge revealed the presence of some under-coordinated TiO5 units created because of the partial replacement of Fe3+ ions in the Ti4+. site. UV-visible absorption spectra indicated a reduction in optical gap with increasing Fe content. The electronic structure and spin densities of STFO with x = 0, 0.0625, 0.125, 0.5, and 1 are calculated by the OFT method at the B3LYP computational level, showing a Jahn-Teller distortion of O atoms surrounding the Fe as well as the formation of under-coordinated TiO5 units. From the electrical viewpoint, the results show that STFO is a mixed (ionic and electronic) conductor and that the electronic contribution becomes dominant with increasing Fe content. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Generalitat Valenciana Ministerio de Ciencia e Innovacion Programa de Cooperacion Cientifica con Iberoamerica (Brazil) Ministerio de Educacion Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo, Brazil Univ Jaume 1, Dept Quim Fis & Analit, E-12080 Castellon de La Plana, Spain Univ Estadual Paulista, UNESP, BR-15054000 Sao Paulo, Brazil Univ Fed Sao Paulo, UNIFESP, BR-12231280 Sao Paulo, Brazil Univ Fed Pelotas, BR-96160000 Pelotas, RS, Brazil Univ Estadual Paulista, UNESP, BR-15054000 Sao Paulo, Brazil CNPq: 70/2008 CNPq: 150753/2013-6 FAPESP: 13/09573-3 Generalitat ValencianaPrometeo/2009/053 Ministerio de Ciencia e InnovacionCTQ2009-14541-C02 Ministerio de EducacionPHB2009-0065-PC