Pyrochlores. II. An investigation of La2Ce2O7 by neutron diffraction
- 15 March 1967
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 45 (6) , 609-614
- https://doi.org/10.1139/v67-101
Abstract
The lattice parameter of La2Ce2O7 fired at 1 400 °C was found to be 5.5700 ± 7 Å (at 20 ± 2 °C). Its crystal structure was of the disordered fluorite rather than the pyrochlore type. The degree of order in the structure could not be established from the neutron powder diffraction pattern, but it is likely that the metal and oxygen atoms were distributed at random, possibly with some tendency to short-range ordering. It would appear that for Ce4+ the ionic size requirements for the formation of the pyrochlore structure are no longer satisfied, and that the cerates M23+Ce24+O7 are outside the stability limits for 3–4 pyrochlores.Keywords
This publication has 5 references indexed in Scilit:
- DETERMINATION OF THE CRYSTAL STRUCTURE OF ERBIUM TITANATE, Er2Ti2O7, BY X-RAY AND NEUTRON DIFFRACTIONCanadian Journal of Chemistry, 1965
- Thermal Decomposition of Scandium, Yttrium, and Rare Earth Metal OxalatesAnalytical Chemistry, 1958
- Dielectric, X-Ray, and Optical Study of Ferroelectric and Related CompoundsPhysical Review B, 1955
- Fluoritgitter mit leeren AnionenplätzenZeitschrift für anorganische und allgemeine Chemie, 1939
- ?Umweganregung?, eine bisher unbeachtete Wechselwirkungserscheinung bei RaumgitterinterferenzenThe European Physical Journal A, 1937