Phase Transition in Weberite-Type Gd[subscript 3]NbO[subscript 7]

Journal Article · Fri Sep 17 00:00:00 EDT 2010 · J. Am. Ceram. Soc.

DOI:https://doi.org/10.1111/j.1551-2916.2009.03494.x· OSTI ID:1002643

Cai, Lu; Denev, Sava; Gopalan, Venkatraman; Nino, Juan C ^[1]

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1. Florida

Gd{sub 3}NbO{sub 7} has an orthorhombic weberite-type crystal structure and undergoes a phase transition at about 340 K. The phase transition was confirmed by second harmonic generation, heat capacity measurement, and high-resolution X-ray diffraction. Above 340 K, Gd{sub 3}NbO{sub 7} has a centrosymmetric weberite-type structure with space group Cmcm (No. 63) and transforms at about 340 K into a non-centrosymmetric structure with space group Cm2m (No. 38). The phase transition is mainly due to off-center shifts of Nb{sub 5+} ions within NbO{sub 6} octahedra, as well as off-center shifts of one-third of the Gd{sup 3+} ions within GdO{sub 8} polyhedra.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USDOE
• OSTI ID: 1002643
• Journal Information: J. Am. Ceram. Soc., Vol. 93, Issue (3) ; 03, 2010; ISSN 0002-7820
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
HARMONIC GENERATION
SPACE GROUPS
SPECIFIC HEAT
X-RAY DIFFRACTION