Crystal growth and dielectric characterization of crystals derived from the solid-solution Ba<sub>(1−<i>x</i>)</sub>Na<sub><i>x</i></sub>Ti<sub>(1−<i>x</i>)</sub>Nb<sub><i>x</i></sub>O<sub>3</sub> (BTNN)
GACEM, Lakhdar
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Département de physique
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Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Département de physique
GACEM, Lakhdar
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Département de physique
< Réduire
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Département de physique
Langue
en
Article de revue
Ce document a été publié dans
Materials Research Bulletin. 2009, vol. 44, n° 12, p. 2240-2245
Elsevier
Résumé en anglais
Single crystals of (1 − <i>x</i>)BaTiO<sub>3</sub> + <i>x</i>NaNbO<sub>3</sub> (BTNN) for <i>x</i> = 0.84 were obtained by high temperature solution growth using Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub> as solvent. The ...Lire la suite >
Single crystals of (1 − <i>x</i>)BaTiO<sub>3</sub> + <i>x</i>NaNbO<sub>3</sub> (BTNN) for <i>x</i> = 0.84 were obtained by high temperature solution growth using Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub> as solvent. The room temperature crystal structure of BTNN 16/84-phase was determined from X-ray single crystal diffraction data, in the tetragonal system with space group <i>P</i>4<i>bm</i>. The refinement from 246 independent reflections led to the following parameters: <i>a</i> = <i>b</i> = 5.5845(3) Å, <i>c</i> = 3.9453(2) Å, <i>V</i> = 123.041(11) Å<sup>3</sup>, <i>Z</i> = 2, with final <i>cR</i><sub>wp</sub> = 0.150 and <i>R</i><sub>B</sub> = 0.041. The structure of BTNN 16/84-phase can be described as a three-dimensional framework built up from (Nb–Ti)O<sub>6</sub> octahedra with Na and Ba in the dodecahedral site of perovskite-like type. Some mm<sup>3</sup>-sized crystals have been selected and various dielectric measurements (ferroelectric, pyroelectric, and piezoelectric) have been performed. Transition from paraelectric to ferroelectric state at around 460 K has been observed to be in good agreement with ceramics of closer composition. Dielectric, piezoelectric and pyroelectric measurements on crystal confirm the ferroelectric behaviour of BTNN 16/84.< Réduire
Mots clés en anglais
Oxides
Crystal growth
Crystal structure
Dielectric properties
Ferroelectricity
Piezoelectricity
Phase transition
Origine
Importé de halUnités de recherche