In:
Journal of the American Ceramic Society, Wiley, Vol. 61, No. 11-12 ( 1978-11), p. 473-475
Abstract:
Of the two formulas previously reported for the compound on the alumina‐rich side of the system La 2 O 3 ‐Al 2 O 3 , present experimental results indicate that LaAl 11 O 18 is correct. This compound melts congruently at ∼2000°C and has a hexagonal structure with lattice parameters of a 0 = 5.561± 0.007 Å and c 0 =22.041± 0.004 Å. Compositions fired at 1650° showed invariant powder diffraction patterns whereas those fired at 1450°C exhibited X‐ray patterns which varied both in numbers and relative intensities of lines. When the samples which had been initially fired at 1450° were refired at 1650°, the X‐ray patterns changed to the invariant 1650°C pattern. This behavior appears to be related to an ordering mechanism in which the La 3+ cations are distributed between two types of cation sites in the hexagonal lattice.
Type of Medium:
Online Resource
ISSN:
0002-7820
,
1551-2916
DOI:
10.1111/jace.1978.61.issue-11-12
DOI:
10.1111/j.1151-2916.1978.tb16119.x
Language:
English
Publisher:
Wiley
Publication Date:
1978
detail.hit.zdb_id:
2008170-4
detail.hit.zdb_id:
219232-9
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