Peculiarities of the volume magnetostriction in La1-xSrxMnO3 in the Curie point region

Анотація

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-xSr_xMnO₃ 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.