| Full text | |
| Author(s): |
Silveira, Jose V.
[1]
;
Vieira, Luciana L.
[2]
;
Aguiar, Acrisio L.
[3]
;
Freire, Paulo T. C.
[4]
;
Mendes Filho, Josue
[4]
;
Alves, Oswaldo L.
[2]
;
Souza Filho, Antonio G.
[4]
Total Authors: 7
|
| Affiliation: | [1] Univ Fed Ceara, Dept Engn Comp, Sobral, CE - Brazil
[2] Univ Estadual Campinas, Lab Solid State Chem, Inst Quim, Campinas, SP - Brazil
[3] Univ Fed Piaui, Dept Fis, Teresina, PI - Brazil
[4] Univ Fed Ceara, Dept Fis, POB 6030, BR-60455900 Fortaleza, Ceara - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY; v. 193, p. 47-53, MAR 15 2018. |
| Web of Science Citations: | 4 |
| Abstract | |
MoO3 nanoribbons were studied under different pressure conditions ranging from 0 to 21 GPa at room temperature. The effect of the applied pressure on the spectroscopic and morphologic properties of the MoO3 nanoribbons was investigated by means of Raman spectroscopy and scanning electron microscopy techniques. The pressure dependent Raman spectra of the MoO3 nanoribbons indicate that a structural phase transition occurs at 5 GPa from the orthorhombic alpha-MoO3 phase (Pbnm) to the monoclinic MoO3-II phase (P-21/m), which remains stable up to 21 GPa. Such phase transformation occurs at considerably lower pressure than the critical pressure for alpha-MoO3 microcrystals (12 GPa). We suggested that the applanate morphology combined with the presence of crystalline defects in the sample play an important role in the phase transition of the MoO3 nanoribbons. Frequencies and linewidths of the Raman bands as a function of pressure also suggest a pressure induced morphological change and the decreasing of the nanocrystal size. The observed spectroscopic changes are supported by electron microscopy images, which clearly show a pressure-induced morphologic change in MoO3 nanoribbons. (C) 2017 Elsevier B.V. All rights reserved. (AU) | |