Peculiarities of the volume magnetostriction in La1-xSrxMnO3 in the Curie point region
L. I. Koroleva, A. I. Abramovich, R. V. Demin, and A. V. Michurin
M. V. Lomonosov Moscow State University, Vorobyevy Gory, Moscow 119899, Russia
Received September 25, 2000
The parallel l|| and perpendicular l^ magnetostriction with respect to the applied magnetic field and the thermal expansion Dl/l are studied on La1-xSrxMnO3 single crystals with x=0.1, 0.15, and 0.3. For the conducting sample with x=0.3 and the semiconducting sample with x=0.15 the volume magnetostriction (w=l||+2l^) is negative and the |w|(T) curves go through a maximum at the Curie point TC. At T > TC its Dl/l temperature dependence is stronger than the linear one. For the semiconducting sample with x=0.1 w is negative at T < TC and |w|®0 at T~TC. Its Dl/l is linear at T≥TC. The behavior of w and Dl/l are explained by a magnetic two-phase state, due to strong s-d exchange.