Neutron diffraction studies of cubic tungsten bronzes
1976; Elsevier BV; Volume: 17; Issue: 1-2 Linguagem: Inglês
10.1016/0022-4596(76)90206-1
ISSN1095-726X
AutoresPhilip J. Wiseman, P.G. Dickens,
Tópico(s)Nuclear materials and radiation effects
ResumoPowder neutron diffraction studies of Li0.36WO3, Na0.73WO3 and La0.14WO3 show them to be isostructural with cubic D0.53WO3. Apart from La0.14WO3, all have distorted perovskite structures described by a body centered unit cell (Im3) containing eight formula weights. The distortion, which decreases in the order D ∼ Li > Na creates two crystallographically inequivalent A sites: 12 coordinate (0,0,0) and 4 coordinate (12,12,0). Although precise occupation numbers of these sites could not be determined directly, it is probable that the lithium atoms are ordered into the 4 coordinate sites. La0.14WO3 has the simple perovskite structure with a random distribution of lanthanum atoms over the 12 coordinate A sites. Comparative features of the cubic tungsten bronze structures are discussed.
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