Abstract
The comparative investigation of low (110K) and high-temperature (573 K) ferroelastic phase transitions in Ba2NaNb5O15 crystal was carried out by low-frequency inverted torsion pendulum. The anomalies of elastic and anelastic properties, corresponding to the phase transitions are differed essentially. A large and a wide internal friction peak was also observed at 228 K. A possible nature of mechanical loss is discussed in frame of domain wall dynamics in a crystal with defects.