Persistent magnetoresistive memory in phase separated manganites

Abstract We have studied magnetic and transport properties on different manganese-oxide-based compounds exhibiting phase separation: polycrystalline La 5/8− y Pr y Ca 3/8 MnO 3 ( y =0.3) and La 1/2 Ca 1/2 Mn 1− z Fe z O 3 ( z =0.05), and single crystals of La 5/8− y Pr y Ca 3/8 MnO 3 ( y ∼0.35). Time dependent effects indicate that the fractions of the coexisting phases are dynamically changing in a definite temperature range. We found that in this range the ferromagnetic fraction “ f ” can be easily tuned by application of low magnetic fields ( f ” and can be recovered through transport measurements. This effect is due both to the existence of a true phase separated equilibrium state with definite equilibrium fraction “ f 0 ”, and to the slow growth dynamics. The fact that the same global features were found on different compounds and in polycrystalline and single crystalline samples, suggests that the effect is a general feature of some phase separated media.