Structural Aspects of the Crystallographic-Magnetic Transition in LaVO3 around 140 K
| Autor: | Sang-Wook Cheong, A. Santoro, M. Marezio, Qingzhen Huang, Bertram Batlogg, C. S. Oglesby, Pierre Bordet, Hidenori Takagi, C. Chaillout |
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| Rok vydání: | 1993 |
| Předmět: |
Materials science
Neutron diffraction Crystal structure Atmospheric temperature range Condensed Matter Physics Electronic Optical and Magnetic Materials Inorganic Chemistry Crystallography Lattice constant X-ray crystallography Materials Chemistry Ceramics and Composites Orthorhombic crystal system Physical and Theoretical Chemistry Isostructural Monoclinic crystal system |
| Zdroj: | Journal of Solid State Chemistry. 106:253-270 |
| ISSN: | 0022-4596 |
| DOI: | 10.1006/jssc.1993.1285 |
| Popis: | The perovskite-like compound LaVO[sub 3] undergoes a crystallographic-antiferromagnetic transition at about 140 K. The structure of LaVO[sub 3] has been determined at room temperature and just above (150 K) and below (100 K) the transition. Synchrotron X-ray and neutron powder diffraction techniques were used. The lattice parameter variation vs temperature and the structural refinements revealed that above the transition the structure of LaVO[sub 3] is of GdFeO[sub 3] type; namely, it is orthorhombic with lattice parameters at room temperature [alpha] = 5.55548, b = 7.84868, and c = 5.55349 [angstrom] and space group Pnma. The orthorhombic distortion of the structure is very similar to that of isostructural LaFeO[sub 3]. At 100 K, below the transformation temperature, the structure is monoclinic with lattice parameters: a = 5.59360, b = 7.75951, c = 5.56490 [angstrom], [gamma] - 90.125[degrees] and space group P2[sub 1]/a. In the orthorhombic structure all V sites are equivalent, but two independent sites, V1 and V2, are observed in the monoclinic structure. These two sites form alternate layers along the b axis. Above the transition, all the V octahedra are tilted around the three crystallographic axes and are elongated along the [110] direction. The elongation increases at the transitionmore » and occurs in different directions 90[degrees] apart, in the V1 and V2 octahedra.« less |
| Databáze: | OpenAIRE |
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