Temperature study of potassium niobate (KNbO3) elastic constants by brillouin spectroscopy

This study deals with using Brillouin spectroscopy to determine the temperature variation of potassium niobate elastic constants. Two different samples have been used (Y- and Z-cut), and all the measurements were done in the temperature range between 300 K and 420 K. The calculations concern only the first-order coefficients. The acoustic velocity is then determined for each sample in 3 directions of propagation. Results are given for C₂₂, C₅₅, and C₆₆ elastic constants and accuracy problems are discussed.