Low field magnetoelectric and magnetotransport properties of sol–gel grown nanostructured LaMnO₃ manganites

In this communication, we report the results of the studies on dielectric, electroresistance (ER), magnetoresistance (MR) and electric pulse induced resistance (EPIR) change properties under low applied magnetic field of 5 kOe for nanostructured LaMnO₃ manganites synthesized by sol–gel method. Final product of LaMnO₃ was annealed at different temperatures under air and oxygen environments to understand the role of oxygen in governing the electric and transport properties of the manganites. X–ray diffraction (XRD) measurements have been performed to investigate the structural behavior while transmission electron microscopy (TEM) measurements have been carried out to understand the particle size morphology. A strong effect of particle size and annealing environment on the dielectric behavior under applied magnetic field for the samples has been discussed on the basis of oxygen content. Variation in sample resistance with applied DC current shows a high ER values finely controlled by magnetic field. MR and its dependence on the annealing temperature and environment have been understood in the context of phase co–existence scenario. Attempt has been made to understand the EPIR behavior under different applied AC voltages and magnetic fields. Magneto – EPIR (MEPIR) studies have been performed to open a new era of technology for better spintronic based thin film devices. - Highlights: • Single phasic nanostructured manganites can be synthesized at low temperatures. • Sol–Gel technique is low cost, simple and easy to handle. • Strong effect of phase co–existence. • Magnetic field controlled electroresistance. • Large magneto–electric pulsed induced resistance change.