Phase formation, structural and microstructural characterization of novel oxynitride- perovskites synthesized by thermal ammonolysis of (Ca,Ba)MoO.sub.4./sub. and (Ca,Ba)MoO.sub.3./sub..

0314339 - FZÚ 2009 RIV US eng J - Journal Article
Logvinovich, D. - Aguirre, M.H. - Hejtmánek, Jiří - Aguiar, R. - Ebbinghaus, S.G. - Reller, A. - Weidenkaff, A.
Phase formation, structural and microstructural characterization of novel oxynitride- perovskites synthesized by thermal ammonolysis of (Ca,Ba)MoO₄ and (Ca,Ba)MoO₃.
[Syntéza a strukturní a mikrostrukturní charakterizace nových oxinitridů - perovskitů syntetizovaných termální amonolýzou (Ca,Ba)MoO₄ a (Ca,Ba)MoO₃.]
Journal of Solid State Chemistry. Roč. 181, č. 9 (2008), s. 2243-2249. ISSN 0022-4596. E-ISSN 1095-726X
Institutional research plan: CEZ:AV0Z10100521
Keywords : oxynitride * molybdate * crystal
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.910, year: 2008

Reactions of AMoO4 and AMoO3 (A= Ca2+, Ba2+) with ammonia were investigated at 873 K< T < 1123 K with the particular intention to synthesize novel oxynitride-perovskites of the general composition AMo(O,N)3 and to study their crystal structure. CaMo(O,N)3 and BaMo(O,N)3 were prepared by thermal ammonolysis of the corresponding CaMoO3 and BaMoO3 precursors at T = 898 and 998 K. CaMo(O,N)3 crystallizes in the GdFeO3 distorted perovskite structure with orthorhombic space group Pbnm and a = 5.5029(1)A°, b = 5.5546(1)A°, c = 7.8248(1)A°. Its O/N content refined from the ND corresponds to the composition CaMoO1.7(1)N1.3(1). BaMo(O,N)3 crystallizes in the cubic perovskite structure with space group Pm3m and a = 4.0657(1)A°.

Reakce AMoO4 a AMoO3 (A= Ca2+, Ba2+) s amoniakem v rozmezi teplot 873 K< T < 1123 K umoznuji syntetizovat nove oxinitridy-perovskity o slozeni AMo(O,N)3. Takovym zpusobem byly pripraveny CaMo(O,N)3 a BaMo(O,N)3 a jejich krystalova struktura byla podrobne studovana. CaMo(O,N)3 ma struktruru GdFeO3 - prostorova grupa Pbnm - a mrizove parametry a = 5.5029(1)A° , b = 5.5546(1)A°, c = 7.8248(1)A°. Obsah O/N urceny pomoci ND odpovida vzorci CaMoO1.7(1)N1.3(1). BaMo(O,N)3 je kubicky perovskit symetrie Pm3m s a = 4.0657(1)A°.
Permanent Link: http://hdl.handle.net/11104/0004819