Synthesis of La0.67Sr0.33MnO3 and polyaniline nanocomposite with its electrical and magneto-transport properties

Abstract

We have synthesized composite of polyaniline nanotubes with lanthanum strontium manganite (La0.67Sr0.33MnO3) (LSMO) nanoparticles. Scanning electron microscopy, x-ray diffraction, Fourier transform infrared, and thermogravimetric analysis scans are done for morphological, structural, and thermal characterization of polyaniline-LSMO nanocomposite. Room temperature hysteresis loop shows ferromagnetic behavior of polyaniline-LSMO nanocomposite but with very low saturation magnetization. Overall pattern of temperature dependence of resistivity for polyaniline has been best-fitted with the form ln[ρ(T)]∝T−1/2. This may be attributed to quasi-one dimensional hopping and also tunneling between mesoscopic ferromagnetic metallic islands. Total resistivity due to grain and grain boundary reduces by application of magnetic field. Remarkable increase (∼73%) in magnetoresistance (MR) is obtained in these polymer coated LSMO compared to the without coated counterpart (16%). The MR% is found to increase with the increase in percentage of LSMO nanoparticles content in the composite. Temperature and magnetic field dependence of MR is observed. This nanocomposite can be used as a sensitive giant MR sensor.

Studies on La0.67Ca0.33MnO3–SrTiO3 composites using two-phase model

“…Many groups have attempted to synthesize CMR-insulator composites, such as La 0.67 Ca 0.33 MnO 3 (LCMO)-MgO [11], LCMO-BaTiO 3 (BTO) [12,13], LCMO-Al 2 O 3 [14,15], La 0.67 Sr 0.33 MnO 3 -La 2 O 3 -La(OH) 3 [16], La 0.67 Sr 0.33 MnO 3 -polyaniline [17] and LCMO-SrTiO 3 (STO) [18], etc. Incorporation of insulating materials as a second phase is believed to be advantageous to enhance extrinsic CMR behaviour as they make the GBs insulating, thus creating a barrier in the way of the charge carriers followed by an enhancement of tunneling probability.…”

“…For a better understanding of CMR a large number of studies have been carried out in single crystals [6], thin films [7,8], polycrystalline CMR materials [9,10] and CMR-based composites [11][12][13][14][15][16][17][18]. Many groups have attempted to synthesize CMR-insulator composites, such as La 0.67 Ca 0.33 MnO 3 (LCMO)-MgO [11], LCMO-BaTiO 3 (BTO) [12,13], LCMO-Al 2 O 3 [14,15], La 0.67 Sr 0.33 MnO 3 -La 2 O 3 -La(OH) 3 [16], La 0.67 Sr 0.33 MnO 3 -polyaniline [17] and LCMO-SrTiO 3 (STO) [18], etc.…”

Magnetocaloric effect in composite structures based on ferromagnetic–ferroelectric Pr0.6Sr0.4MnO3/BaTiO3 perovskites

“…A big interest is being paid to multiferroic materials with coupled electric and magnetic properties because they can exhibit both electrical polarization induced by a magnetic field and magnetization induced by an electric field [5][6][7][8][9]. If these materials are to be used in practical applications, it is necessary to make a composite of magnetic and electric compounds with an improved magnetoelectric effect.…”

Recent Trends and Developments in Conducting Polymer Nanocomposites for Multifunctional Applications

“…The surface area of conducting polymer films can be increased by titanium and carbon nanotubes to store drugs [127,128]. Many therapeutic drugs, such as 2-ethylhexyl phosphate, dopamine, naproxen, heparin, and dexamethasone, have been bound and successfully released from these polymers [129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144].…”