کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1332628 | 979048 | 2007 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Crystal structure of Ln1/3NbO3 (Ln=Nd, Pr) and phase transition in Nd1/3NbO3 Crystal structure of Ln1/3NbO3 (Ln=Nd, Pr) and phase transition in Nd1/3NbO3](/preview/png/1332628.png)
The crystal structure of the A-site deficient perovskite Ln1/3NbO3 (Ln=Nd, Pr) at room temperature has been determined, for the first time, as orthorhombic in space group Cmmm using high-resolution neutron powder diffraction. Pertinent features are the alternation of unoccupied layers of A-sites and layers partly occupied by Ln cations, as well as out-of-phase tilting of the NbO6 octahedra around an axis perpendicular to the direction of the cation/vacancy ordering. The phase transition behaviour of Nd1/3NbO3 has also been studied in situ. This compound undergoes a continuous phase transition at around 650 °C to a tetragonal structure in space group P4/mmm due to the disappearance of the octahedral tilting. The analysis of spontaneous strains shows that this phase transition is tricritical in nature.
Temperature dependence of the measured lattice parameters through the orthorhombic to tetragonal phase transition in the A-site deficient perovskite Nd1/3NbO3.Figure optionsDownload as PowerPoint slide
Journal: Journal of Solid State Chemistry - Volume 180, Issue 6, June 2007, Pages 1846–1851