Depression of the ferroelastic phase transition in LiCsSO4 by uniaxial stress

✍ Scribed by Tylczyński, Zbigniew

• Book ID: 111489227
• Publisher: Walter de Gruyter GmbH
• Year: 2011
• Tongue: English
• Weight: 503 KB
• Volume: 9
• Category: Article
• ISSN: 2391-5471
• DOI: 10.2478/s11534-010-0064-2

✦ Synopsis

In the lithium-caesium sulphate crystal in the temperature range of ferroelastic phase transition, the uniaxial stress σ X induced changes in velocity and attenuation of the longitudinal ultrasonic wave propagating in the direction [010] are studied. The phase transition is close to the three-critical point and the critical exponent is κ = 0 27 ± 0 02. The stress applied drastically decreases the stepwise change in the wave velocity at T C up to its disappearance at 2 MPa. In the temperature range between T C and T C -6 K, the stress leads to an increase in the wave velocity and a decrease in its attenuation. This range was interpreted as that of co-existence of ferroelastic and incommensurate ordering, in which the stress influences the density of solitons leading to stiffening of the crystal lattice.