Synthesis, structure and magnetic properties of the new oxygen-deficient perovskite Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub>
Langue
en
Article de revue
Ce document a été publié dans
Solid State Sciences. 2011, vol. 13, n° 6, p. 1235-1241
Elsevier
Résumé en anglais
The new ternary vanadate Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub> has been synthesized by solid state reaction route. Its crystal structure was determined from both powder X-ray diffraction data and high-resolution ...Lire la suite >
The new ternary vanadate Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub> has been synthesized by solid state reaction route. Its crystal structure was determined from both powder X-ray diffraction data and high-resolution transmission electron microscopy (HRTEM) analysis. Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub> (<i>P</i>2<i>/c</i>, <i>a</i> = 7.4004(4) Å, <i>b</i> = 5.6065(3) Å, <i>c</i> = 17.0876(11) Å, <i>β</i> = 90.0114(2) °, and <i>Z</i> = 4) crystallizes with a new type of oxygen-deficient perovskite ABO<sub>3-δ</sub> (<i>δ</i> = 1/2) with the sodium atoms occupying the A site and the vanadium and manganese atoms perfectly ordered in the B site. In Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub> the manganese and the vanadium atoms are octahedral and tetrahedral coordinated, respectively. The MnO<sub>6</sub> and VO<sub>4</sub> polyhedra share edges and form a perovskite 3D-framework with high disorder of the oxygen atoms. HRTEM confirmed this structural model. Na<sub>3</sub>MnV<sub>2</sub>O<sub>7.5</sub> was characterized by magnetic susceptibility and specific heat measurements. It is antiferromagnetic with no magnetic ordering down to 2 K.< Réduire
Mots clés
Crystal structure
Magnetic measurements
Perovskite
Vanadates
HRTEM
Origine
Importé de halUnités de recherche