| Numéro |
J. Phys. III France
Volume 2, Numéro 6, June 1992
|
|
|---|---|---|
| Page(s) | 1029 - 1038 | |
| DOI | https://doi.org/10.1051/jp3:1992176 | |
DOI: 10.1051/jp3:1992176
J. Phys. III France 2 (1992) 1029-1038Piezothermal analysis of the N
A. Anakkar1, J. M. Buisine1, C. Alba-Simionesco2, L. Ter Minassian2, H. T. Nguyen3 and C. Destrade3
1 Equipe de Dynamique et Structure des Matériaux Moléculaires, U.A. CNRS n° 801, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France
2 Laboratoire de Chimie Physique, Université Pierre et Marie Curie, U.A. CNRS n° 176, U.A. CNRS n° 721, 11 rue P. et M. Curie, 75231 Paris Cedex, France
3 Centre de Recherche Paul Pascal, Domaine Universitaire, 33405 Talence Cedex, France
© Les Editions de Physique 1992
J. Phys. III France 2 (1992) 1029-1038
Piezothermal analysis of the N
-S
transition on small samples of p-octylbenzoate p-cyanobenzoyloxyphenyl
A. Anakkar1, J. M. Buisine1, C. Alba-Simionesco2, L. Ter Minassian2, H. T. Nguyen3 and C. Destrade3
1 Equipe de Dynamique et Structure des Matériaux Moléculaires, U.A. CNRS n° 801, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France
2 Laboratoire de Chimie Physique, Université Pierre et Marie Curie, U.A. CNRS n° 176, U.A. CNRS n° 721, 11 rue P. et M. Curie, 75231 Paris Cedex, France
3 Centre de Recherche Paul Pascal, Domaine Universitaire, 33405 Talence Cedex, France
(Received 16 December 1991, accepted 27 February 1992)
Abstract
In order to detect weakly first-order phase transitions by means of piezothermal measurements on small samples of calamitic
mesogens exhibiting reentrant phenomena, a new high pressure calorimeter equipped with a composite slab thermostat has been
built. Its efficiency has been proved and its performances determined. Its use on a ten cubic millimeter effective volume
of p-octylbenzoate p-cyanobenzoyloxyphenyl has permitted to prove the N
-S
transition is not purely second order but weakly first-order.
© Les Editions de Physique 1992