Depression of the ferroelastic phase transition in LiCsSO4 by uniaxial stress

作者：Tylczynski Zbigniew^*

来源：Central European Journal of Physics, 2011, 9(3): 722-728.

DOI：10.2478/s11534-010-0064-2

• lithium-caesium sulfate
• ferroelastic phase transition
• ultrasonic wave propagation
• uniaxial stress

In the lithium-caesium sulphate crystal in the temperature range of ferroelastic phase transition, the uniaxial stress sigma (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 kappa = 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.

• 出版日期2011-6