Temperature dependence Raman spectroscopy and DFT calculations of Bi 2 (MoO 4 ) 3 .

Autor: Saraiva GD; Faculdade de Educação Ciências e Letras do Sertão Central, Universidade Estadual do Ceará, CEP 63.902-098 Quixadá, CE, Brazil. Electronic address: gilberto.saraiva@uece.br., da Silva Filho JG; Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410, Brazil., Saraiva-Souza A; Departamento de Física, Universidade Federal do Maranhão (UFMA), Campus Universitário do Bacanga, São Luís, Maranhão 65080-805, Brazil., de Castro AJR; Universidade Federal do Ceará - Campus Quixadá, Cedro, Quixadá, Ceará 63902-580, Brazil., Teixeira AMR; Departamento de Física, Universidade Regional do Cariri, Juazeiro do Norte, CE 63040-000, Brazil., Luz-Lima C; Departamento de Física, Campus Ministro Petrônio Portella, Universidade Federal do Piauí, CEP 64.049-550 Teresina, PI, Brazil., Oliveira FGS; Departmento de Engenharia Metalúrgica e de Materiais, Universidade Federal do Ceará, Fortaleza Brasil, CEP 63.900-000 Fortaleza, CE, Brazil., Neto VOS; Faculdade de Educação Ciências e Letras do Sertão Central, Universidade Estadual do Ceará, CEP 63.902-098 Quixadá, CE, Brazil., Freire PTC; Departamento de Física, Universidade Federal do Ceará, P. O. Box 6030, CEP 60.455-970 Fortaleza, CE, Brazil., de Sousa FF; Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CEP 66075-110 Belém, PA, Brazil.
Jazyk: angličtina
Zdroj: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy [Spectrochim Acta A Mol Biomol Spectrosc] 2020 Jan 05; Vol. 224, pp. 117340. Date of Electronic Publication: 2019 Jul 05.
DOI: 10.1016/j.saa.2019.117340
Abstrakt: This work reports a theoretical and experimental study on the electronic and vibrational properties of Bi 2 (MoO 4 ) 3 . First-principle calculations were applied to increase the understanding on the properties of the chemical composition through the energy bands. The conduction band minimum (CBM) is found at the high symmetric Γ-point, while the valence-band maximum (VBM) is located between the Z and the Γ-points. Therefore, these facts confirm that the Bi 2 (MoO 4 ) 3 crystal is a semiconductor compound with an indirect band-gap of about 2.1 eV. Moreover, lattice dynamic properties were calculated using density functional perturbation theory (DFPT) in order to assign the experimental Raman bands. In addition, we performed temperature-dependent Raman spectroscopic studies in the Bi 2 (MoO 4 ) 3 crystals to obtain information on structural changes induced by effects of the temperature change. From the changes observed in the Raman spectra phase transitions at ∼ 668 and 833 K were inferred, with the last one possibly related to the disorder due to the heating process.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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