Insight into the Effects of Fe Addition on the Local Structure and Electronic Properties of SrTiO3

Autor(es)

da Silva, Luis F. ^[1] ; M'Peko, Jean-Claude ^[1] ; Andres, Juan ^[2] ; Beltran, Armando ^[2] ; Gracia, Lourdes ^[2] ; Bernardi, Maria I. B. ^[1] ; Mesquita, Alexandre ^[3] ; Antonelli, Eduardo ^[4] ; Moreira, Mario L. ^[5] ; Mastelaro, Valmor R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo - Brazil

^[2] Univ Jaume 1, Dept Quim Fis & Analit, E-12080 Castellon de La Plana - Spain

^[3] Univ Estadual Paulista, UNESP, BR-15054000 Sao Paulo - Brazil

^[4] Univ Fed Sao Paulo, UNIFESP, BR-12231280 Sao Paulo - Brazil

^[5] Univ Fed Pelotas, BR-96160000 Pelotas, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 118, n. 9, p. 4930-4940, MAR 6 2014.
• Citações Web of Science: 29

Resumo

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. (AU)

• Processo FAPESP: 13/09573-3 - Síntese e Caracterização de Heteroestruturas de ZnO/SnO2 obtidas pelo Método Hidrotermal: Aplicação como Sensores de Gás
• Beneficiário: Luís Fernando da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado