MIXED VALENCE EUROPIUM PEROVSKITES IN THE SYSTEM Eu-Ta-O.
Abstract
Contrary to previous reports the phase near Eu//2**I**IEu**I**I**ITaO//6 is not a cubic perovskite but distorted. Precession photographs give evidence for a monoclinic cell a equals 8. 28 b equals 5. 91 c equals 5. 84 beta greater than 90 degree . A similar cell has been suggested for Sr//2Eu**I**I**ITaO//6 from powder data.