  Magnetic field induced step-like changes in magnetization and resistivity of
SmSr manganites were studied. A strong dependence of these features on the
cooling rate was observed. Magnetostriction, however, does not show the
presence of large strain in our samples. From all these features we can rule
out the conventional explanation of magnetization jumps as a consequence of
martensitic transition. We propose instead that quenched by fast cooling
disorder leads to the formation of an inhomogeneous metastable state and to
subsequent magnetization jumps.
