Transmission Electron Microscopy and Neutron Powder Diffraction Studies of GdFeO3 Type SrNbO3

Stoichiometric SrNbO3; with a GdFeO3 type structure was synthesized between 1300 and 1550° C in Ar-filled and sealed niobium ampoules. Its crystal structure was refined using time-of-flight neutron diffraction data. Space group Pnma: a=2·ap=5.6894(2) ?; b=2·ap=8.0684(1) ?; c=2· ap=5.6944(2) ?; RF2=0.020; and RP=0.034. High-resolution electron microscopy and electron diffraction studies frequently revealed structural defects in SrNbO3. X-ray and electron diffraction studies showed cubic symmetry for SrNbO3 synthesized below 1300°C and for compounds with nominal composition Sr0.8NbO3 synthesized between 1200 and 1550°C. SrNbO3 was found to be temperature independently paramagnetic.