Ordering behaviour of the mineral lawsonite

Autor(en)

Peter Sondergeld, Wilfried Schranz, Andri V Kityk, Michael Allan Carpenter, Eugen Libowitzky

Abstrakt

Lawsonite crystals have been investigated by dilatometry and dynamic mechanical analysis as well as by measurements of the optical birefringence and the dielectric constant in the temperature range 90 K = T = 633 K. Two successive phase transitions have been found at low temperatures. The analysis of the spontaneous strain and the excess birefringence data reveals that the transition around 273 K (T1) is tricritical. The other transition around 120 K (T2) is of second order and proper ferroelectric. The mineral shows remarkable pretransitional effects in a temperature range up to 200 K above T1. The data below T2 are interpreted in terms of a mutual interference of the two different ordering processes associated with T1 and T2, respectively.

Organisation(en)

Institut für Mineralogie und Kristallographie

Externe Organisation(en)

University of Cambridge, Czestochowa University of Technology (CUT)

Journal

Phase Transitions: a multinational journal

Band

71

Seiten

189-203

Anzahl der Seiten

15

ISSN

0141-1594

DOI

https://doi.org/10.1080/01411590008229651

Publikationsdatum

2000

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5375e1fb-747f-43f7-9efc-fd19fadcacdd