Magnetoelastic anomalies and suppression of Jahn-Teller distortions in La1-xSrxMnO3 by pulsed magnetic fields

Thermal expansion Delta l/l(T) and magnetostriction lambda(parallel to,perp endicular to)(H,T) in the pulsed magnetic fields H up to 250 kOe were studi ed in the single La1-xSrxMnO3 crystals (x = 0.1, 0.125, and 0.15) at temper atures T = 10-320 K. Anomalies in the Delta l/l(T) curves were observed nea r a charge (polaron) ordering (Tp) and structural transitions between ortho rhombic Jahn-Teller distorted O' phase and high temperature orthorhombic (p seudocubic) O* one (T-s'). A noticeable increase in the field-induced magne tostriction lambda(parallel to,perpendicular to)(H) Was revealed in the O' phase at T-p < T < T-s'. jumps in the lambda(parallel to,perpendicular to)( H) curves were observed at temperatures near Tp The observed features may b e related to a suppression of the Jahn-Teller O' phase by the magnetic fiel d and field induced transition to a new orbital-ordered ferromagnetic state .