Elastic properties of La$_{0.82}$Ca$_{0.18}$MnO$_{3}$ single crystal

The temperature dependences of the velocity of longitudinal sound waves and the internal friction in a La$_{0.82}$Ca$_{0.18}$MnO$_{3}$ single crystal with the Curie temperature $T_{C}$ = 181 K have been studied. As temperature decreases, the single crystal is shown to undergo the transition from the pseudocubic $O^*$ to the Jahn–Teller $O’$ phase at $T\sim$ 254 K and the reverse transition from $O’$ to $O^*$ phase at $T\sim$ 84 K. The velocity of sound and the internal friction in the $O’$ phase are found to be significantly smaller than those in the $O^*$ phase.