title: High pressure Raman scattering study on Sm2Mo4O15system.
abstract: High-pressure Raman experiments were performed on Sm2Mo4O15system up to 7.9GPa. We show that this system exhibits an irreversible structural amorphization at 5.0GPa. In contrast to any other molybdates and tungstates experiencing pressure-induced amorphization, this structural change in Sm2Mo4O15has strongly first-order character. This amorphous phase can be originated from the hindrance of a crystalline structural phase transition from the P1¯ to P2/m structure. Additionally, the assignment of Raman modes of the ambient-pressure phase of Sm2Mo4O15was proposed based on lattice dynamics calculations.
authors.affiliation: Faculdade de Física, Universidade Federal do Pará, P.O. Box 479, Belém, PA 66075-110, Brazil.
authors.forename: S D
authors.initials: SD
authors.lastname: Silva Santos
authors.affiliation: Faculdade de Física, Universidade Federal do Pará, P.O. Box 479, Belém, PA 66075-110, Brazil. Electronic address: wparaguassu@pq.cnpq.br.
authors.forename: W
authors.initials: W
authors.lastname: Paraguassu
authors.affiliation: Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Maczka
authors.affiliation: Departamento de Física, Universidade Federal do Ceará, P.O. Box 6030, Fortaleza, CE, 60455-900, Brazil.
authors.forename: P T C
authors.initials: PTC
authors.lastname: Freire
keywords: Hydrostatic pressure; Molybdates; Negative thermal expansion; Phonon calculation; Pressure induced amorphization; Raman scattering; Structural phase transition