Title: ПРАВИЛА ОФОРМЛЕНИЯ ТЕЗИСОВ КОНФЕРЕНЦИИ ВНКСФ-7
Author: Sergey Trapeznikov
Last saved by: Андрей
Company: Saint-Petersburg State University

Specialization: 010700/03  Physics of condensed state of matter
Program: 41  Coherent phonons and NMR in solids
Head of the program: prof. E.V. Charnaya
Department of Solid State Physics
Scientific adviser: assistant prof. B. F. Borisov
Reviewer: assistant prof. S.A. Ktitorov

Size effects for ferroelastic phase transition
A.V. Stolbova 

Recently a great attention is given to studies of nanostructured materials, and particularly, of nanocomposites obtained via loading of porous matrices with various substances because of their importance for both fundamental and applied physics. Nanocomposites on the base of ferroelastic materials are of a special interest.
Acoustic studies of nanocomposites on the base of molecular sieves MCM-41 with pore sizes 3.7 and 2.6 nm filled with ferroelastic LiCsSO_4 and nanocomposites porous glass–LiCsSO_4 were carried out. The ferroelastic phase transition in such systems was found from critical anomaly in velocity of acoustic waves. The phase transition was shifted to low temperatures compared with that in bulk LiCsSO_4, and the dependence of the phase transition temperature on inverse pore size has a nonlinear character. The absence of thermal hysteresis and reversible behavior of the velocity near the phase transition confirm that the transition remains of the second order as in bulk. The decrease of the transition temperature can be treated on the base of the Landau phenomenological model for size effects in small particles. 
The performed studies showed that acoustic technique is a very useful for studying ferroelastic phase transitions under nanoconfinement.

The list of the publication
1. A. Stolbova. Ferroelastic phase transition in LiCsSO_4/MCM-41 nanocomposite. // Conference abstracts International Student Conference “Science and Progress”, St. Petersburg – Peterhof, 2011. p.124.
2. B.F. Borisov, E.V. Charnaya, A.L. Pirozerskii, А.V. Stolbova. Ferroelastic phase transition in nanopaticles of LiCsSO_4 embedded in the pores of molecular sieve MCM-41 // Conference abstracts «Lomonosovskie chteniya». Moscow, 2011. p. 59-61.