Vibrational study of A3In2B"O9 (A = Ba, Sr; B" = U, W) double perovskites

被引:11
|
作者
Silva, E. N. [1 ]
Ayala, A. P. [2 ]
Guedes, I. [2 ]
Larregola, S. A. [3 ]
Pinacca, R. M. [3 ]
Viola, M. del C. [3 ]
Pedregosa, J. C. [3 ]
机构
[1] Univ Fed Maranhao, Dept Fis, BR-65000000 Sao Luis, MA, Brazil
[2] Univ Fed Ceara, Dept Fis, BR-60475970 Fortaleza, Ceara, Brazil
[3] Univ Nacl San Luis, Area Quim Gen & Inorgan Dr GF Puelles, Dept Quim, Fac Quim Bioquim & Farm, San Luis, Argentina
关键词
double perovskites; In-U and In-W oxides; FT-IR transmittance; Raman scattering; ORDER-DISORDER; COMPLEX PEROVSKITES; RAMAN-SPECTROSCOPY; CRYSTAL-STRUCTURE; ROOM-TEMPERATURE; SCATTERING; PHASE; GD; MO; SM;
D O I
10.1002/jrs.2225
中图分类号
O433 [光谱学];
学科分类号
0703 ; 070302 ;
摘要
Raman scattering and infrared transmittance techniques were used to investigate the room-temperature phonon spectra of the polycrystalline Ba3In2UO9, Sr3In2UO9, Ba3In2WO9 and Sr3In2WO9 double perovskites. Although X-ray diffraction has shown that both Ba3In2UO9 and Ba3In2WO9 crystallize in a disordered cubic (Pm (3) over barm-O-h(1)) structure with one formula unit per unit cell (Z = 1), Raman measurements revealed that both Ba3In2UO9 and Ba3In2WO9 compounds should exhibit a 1:1 ordered domains with Fm (3) over barm symmetry, embedded in the Pm (3) over barm matrix. Observation of a nu(1)-like vibration of the InO6 octahedron reflects the occurrence of a two-phonon-like behavior due to the intrinsic occupational disorder at octahedral symmetry sites. Assignment of most of the Raman and infrared phonons is also given. Copyright (C) 2009 John Wiley & Sons, Ltd.
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页码:1028 / 1032
页数:5
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