Anomalies of volume magnetostriction and thermal expansion in La1-xSrxMnO3due to magnetic two-phase state

Parallel (lambda(parallel to)) and perpendicular (lambda(perpendicular to)) magnetostriction under an applied magnetic held and thermal expansion Delt a l/l were studied on La1-xSrxMnO3 single crystals with x = 0.1 and 0.3. Fo r conducting sample with x = 0.3, the volume magnetostriction (omega = lamb da(parallel to) + 2 lambda(perpendicular to)) is negative and the \omega\(T ) curves go through maximum at Curie point T-C. At T > T-C, Delta l/l excee ds linear thermal expansion. For semiconductive sample with x = 0.1, omega is negative at T < T-C and \omega\ --> 0 at T similar to T-C. Delta l/l is linear at T greater than or equal to T-C. Behavior of omega and Delta l/l a re explained by a magnetic two-phase state. (C) 1999 Elsevier Science B.V. All rights reserved.