RT Book, Section
T1 Caracterización de la solución sólida Na2(C03,S04) A 550°C
A1 López De Andrés, María Sol
A1 Marcos Pascual, Celia
A1 Cocaño Blanco, Susana
A1 García Martínez, O.
A1 Prieto Rubio, Manuel
AB Although it is known that unlimited solid solution exists for the hightemperature polymorphs Na2S04 (1)and α-Na2C03 , the phase relationships and thevariation of crystallographic parameters for different compositions are not studied.Na2S04 has four well established modifications, but only the high temperaturemodification Na2S04 (1) (Pб3/mmc), stable above 237°C, forms extended solidsolution series with Na2C03. At the other extreme, Na2C03 shows three polymorphsand a rather complicated transition behaviour, being the hexagonal phase α-Na2C03(Pб3/mmc)stable at T > 489°C.In this paper, the crystallographic parameters were determined at 550°C fordifferent solid solution compositions. The study was carried out by X ray diffraction ina high temperature powder camera. The diffraction patterns show a continuousevolution through the entire compositional range. Crystalline spacings and cellparameters decrease as the sulphate content decreases. This fact and the unusualunlimited S04=-C03= substitution can be explained by the orientational disorder oftetrahedral and triangular groups. Theoretical powder diffraction diagrams, calculatedassuming this orientational and substitutional disorder, show a good fit with theexperimentalresults.
PB Univ. Oviedo, Vicerrectorado de Extensión Universitaria
SN 8460552705
YR 1996
FD 1996
LK https://hdl.handle.net/20.500.14352/60545
UL https://hdl.handle.net/20.500.14352/60545
LA spa
DS Docta Complutense
RD 9 jul 2025