Ultrasonic study of perovskite manganites La1-xSrxMnO3

In order to examine the electron-lattice interaction of perovskite manganites with orbital degrees of freedom, we have made the ultrasonic measurements on the hole-doped compounds of La1-xSrxMnO3 (x = 0.12, 0.165). The transverse elastic mode (C-11-C-12)/2 with e(g) symmetry for both x = 0.12 and 0.165 exhibits remarkable softening around the structural phase transition point T-S. This result is ascribed to the Jahn-Teller effect of the e(g) doublet, d(3z(2) - r(2)) and d(x(2) - y(2)), of Mn3+ ions. The elastic softening associated with the charge ordering of the doped Mn4+ in a sea of Mn3+ ions is also presented. (C) 2000 Elsevier Science B.V. All rights reserved.