Peculiarities of the volume magnetostriction in La_{1-x}Sr_{x}MnO_{3} in the Curie point regionL. 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 Abstract The parallel l_{||} and perpendicular l_{^} magnetostriction with respect to the applied magnetic field and the thermal expansion Dl/l are studied on La_{1-x}Sr_{x}MnO_{3} 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 T_{C}. At T > T_{C} its Dl/l temperature dependence is stronger than the linear one. For the semiconducting sample with x=0.1 w is negative at T < T_{C} and |w|®0 at T~T_{C}. Its Dl/l is linear at T≥T_{C}. The behavior of w and Dl/l are explained by a magnetic two-phase state, due to strong s-d exchange. 75.80.+q - Magnetomechanical and magnetoelectric effects, magnetostriction 75.30.Kz - Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.) 75.40.-s - Critical-point effects, specific heats, short-range order (see also 65.40.-b Heat capacities of solids) 74.72.-h - Cuprate superconductors (high-Tc and insulating parent compounds) |