Structural changes at the incommensurate phase transition of Na2CO3

Publisher Website
Google Scholar
Abstract
An analysis is made of the behaviour of the structural parameters of Na 2CO3 as the temperature passes the incommensurate phase transition temperature at 630K. Especially those describing the modulation wave, such as the amplitudes and phases, are studied together with the mean square thermal amplitudes. It appears that the libration of the anion is clearly recognizable in the condensed mode below Tc, as well as in the thermal motion above Tc. However, the transversal acoustic branch, which is unmistakably present in the modulation wave, seems not to show up in the therrmal motion at 655K. For this reason we think that the libration of the CO3‐ion is the driving force in the phase transition. Only very close to the transition temperature it carries the acoustic mode along.

This publication has 0 references indexed in Scilit: