Open AccessDefect properties of vanadium doped barium titanate ceramics
Author(s) -
R. Böttcher,
H. T. Langhammer,
Till Walther,
Frank Syrowatka,
Stefan G. Ebbinghaus
Publication year - 2019
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab4455
Subject(s) - electron paramagnetic resonance , tetragonal crystal system , analytical chemistry (journal) , materials science , valence (chemistry) , vanadium , dopant , hyperfine structure , electron microprobe , ion , barium titanate , titanate , doping , crystallography , crystal structure , ceramic , nuclear magnetic resonance , chemistry , metallurgy , atomic physics , optoelectronics , physics , organic chemistry , chromatography
X-ray diffraction (XRD) patterns, electron probe microanalysis (EPMA), electron paramagnetic resonance (EPR) powder spectra (9 and 34 GHz) and the magnetic susceptibility of BaTiO 3 + 0.04 BaO + 0.01 V 2 O 5 ceramics were studied to investigate the valence states of V ions and their solubility in the BaTiO 3 lattice. In samples sintered at 1400 °C in air, only about 0.1 mol% V is incorporated in the BaTiO 3 lattice being in V 4+ and V 5+ valence state, respectively. 95% of the nominal V dopant content occurs in the secondary phase Ba 3 (V/Ti) 2 O 8 . All BaTiO 3 samples investigated are in tetragonal phase at room temperature. In the as-sintered samples V 4+ is detected at temperatures T 25 K and vanishing at T > 250 K, which is caused by V 2+ ions. This spectrum is characterized by a simultaneous HFS and fine structure splitting constituted by allowed and forbidden transitions. Both V 4+ and V 2+ ions are incorporated at Ti 4+ sites of the BaTiO 3 lattice.