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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Influence of europium doping on the structural phase-transition temperature of beta- and alpha - CoMoa(4) polymorphs

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Autor(es):
Costa, Rosiane K. S. [1] ; Teles, Stefani C. [1] ; de Sousa Filho, Paulo C. [2] ; Dias, Anderson [3] ; Siqueira, Kisla P. F. [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Fed Ouro Preto, Dept Chem, Lab Ceram Mat, Campus Morro do Cruzeiro, ICEB 2, BR-35400000 Ouro Preto, MG - Brazil
[2] Univ Estadual Campinas, UNICAMP, Inst Chem, BR-13083970 Campinas, SP - Brazil
[3] Univ Fed Minas Gerais, ICEx, Dept Chem, CP 702, BR-31270901 Belo Horizonte, MG - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Materials Research Bulletin; v. 118, OCT 2019.
Citações Web of Science: 0
Resumo

This work presents a new possibility to increase the phase transition temperature of CoMoO4 polymorphs (beta and alpha) by europium doping. The material Co0.98Eu0.02MoO4 was produced by the co-precipitation method and its thermochromic property was investigated. An accurate characterization of the material was performed using X-ray diffraction, Raman spectroscopy, diffuse reflectance spectroscopy, thermal analysis, and morphological analysis. The results showed that an irreversible first order phase transition between the two allotropic forms occurred at around 950 degrees C, and it is associated with a drastic color change from purple (beta) to green (alpha). This color change confirmed the promising potential of the material for use as a temperature indicator that could be observed by the naked eye. Photoluminescence spectroscopy helped to elucidate the effect of the presence of europium added to the cobalt molybdate, which also enabled the material to be used as a light emitter under UV excitation. (AU)

Processo FAPESP: 17/11764-2 - Estratégias na síntese de nanomateriais luminescentes para o desenvolvimento de novos sensores ópticos multimodais
Beneficiário:Paulo Cesar de Sousa Filho
Modalidade de apoio: Auxílio à Pesquisa - Regular