On the Question about the Burns Temperature in KTa_1−xNb_xO₃ Ferroelectrics

Abstract

Some present theoretical conceptions and experimental data concerning the existence and location of Burns temperature in relaxor ferroelectrics are discussed. It is shown that dielectric data is unable to locate Burns temperature, whereas both the thermal expansion and acoustic emission data are able to locate it. Based on the thermal expansion and acoustic emission data it is proved that the Burns temperature is located in the range of about 600 K in KTa_1−xNb_xO₃ with x = 32÷37%.

Keywords:

• Relaxor ferroelectrics
• dielectric response
• phase transition
• burns temperature
• intermediate temperature
• acoustic emission