GIANT MAGNETORESISTIVE MEMORY EFFECT IN ND0.7SR0.3MNOZ FILMS

A novel giant magnetoresistance memory effect has been observed in epi taxial Nd0.7Sr0.3MnOz thin films which have previously been found to e xhibit a linear increase in conductivity on first application of magne tic field B. The resistivity of the films depends not only on the inst antaneous applied held but also on the magnetic history of the sample. At T well below the temperature T-p, where the zero-field resistivity has a peak, the film enters a high-conductivity state (upon applicati on of a magnetic field) which persists even when B is reduced to zero. The original ''zero'' field state is not recovered until the sample i s warmed to T similar to T-p. Surprisingly, the dc magnetization exhib its only a weak irreversibility while the magnetoconductivity is marke dly hysteretic. A possible explanation is proposed. (C) 1995 American Institute of Physics.