Influence of Grain Size to Resistivity Relaxation of La_(0.7)Sr_(0.3)MnO_3 Nanoparticles

摘要

The resistivity relaxation in magnetic material is one of the important characteristics for reliable device operations. It also provides insight to the physics of magnetic material. Furthermore, this characteristic is related to the micro structural of the material. In this paper, the resistivity relaxation of different grain sizes of La_(0.7)Sr_(0.3)MnO_3 (LSMO) nanoparticles has been studied. The LSMO nanoparticles was synthesized by sol-gel method and to obtain different grain size, the samples were sintered at different temperatures ranging from 800°C to 1100°C. The resistivity relaxation measurements were recorded for 500-1500s under the influence of magnetic field in range 25-110mT in room temperature. Under the influence of magnetic field, the resistivity of all samples were slowly de-creases as a function of time following logarithmic behavior. Moreover, no saturation was observed in the measurement time span. The resistivity ratio (t)/ (0) as a function of time t was fitted by using logarithmic model. It is shown that resistivity relaxation depends on the grain size and the strength of the magnetic field.