TY - JOUR
T1 - Space group and structure for the perovskite Ca0.5Sr0.5TiO3
AU - Howard, C. J.
AU - Withers, R. L.
AU - Kennedy, B. J.
PY - 2001
Y1 - 2001
N2 - Powder diffraction patterns from Ca1-xSrxTiO3, at x = 0.5, show superlattice peaks indicative of both R-(q = 1/2 [111]p*) and M-(q = 1/2 [110]p*) point octahedral tilting, though the metric is pseudo-tetragonal and indeed very nearly cubic. In a previous study [C. J. Ball, B. D. Begg, D. J. Cookson, G. J. Thorogood, and E. R. Vance, J. Solid State Chem. 139, 238-247 (1998)] this pseudo-tetragonal structure was assigned to space group Cmcm (orthorhombic) rather than to space group Pnma, the accepted space group for the structure of CaTiO3. These two space groups are, however, very difficult to distinguish by powder diffraction techniques. Electron diffraction has been used to obtain diffraction patterns from single domain regions and by such means it has been established unequivocally that the space group at room temperature is not Cmcm but Pnma.
AB - Powder diffraction patterns from Ca1-xSrxTiO3, at x = 0.5, show superlattice peaks indicative of both R-(q = 1/2 [111]p*) and M-(q = 1/2 [110]p*) point octahedral tilting, though the metric is pseudo-tetragonal and indeed very nearly cubic. In a previous study [C. J. Ball, B. D. Begg, D. J. Cookson, G. J. Thorogood, and E. R. Vance, J. Solid State Chem. 139, 238-247 (1998)] this pseudo-tetragonal structure was assigned to space group Cmcm (orthorhombic) rather than to space group Pnma, the accepted space group for the structure of CaTiO3. These two space groups are, however, very difficult to distinguish by powder diffraction techniques. Electron diffraction has been used to obtain diffraction patterns from single domain regions and by such means it has been established unequivocally that the space group at room temperature is not Cmcm but Pnma.
KW - Electron diffraction
KW - Neutron powder diffraction
KW - Perovskite
KW - Space group
KW - Structure
UR - http://www.scopus.com/inward/record.url?scp=0034803739&partnerID=8YFLogxK
U2 - 10.1006/jssc.2001.9229
DO - 10.1006/jssc.2001.9229
M3 - Article
SN - 0022-4596
VL - 160
SP - 8
EP - 12
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
IS - 1
ER -