Structural, magnetic and transport properties of La0.8Sr0.2MnO3/xNiO composites

Eshraghi, M.; Salamati, H.; Kameli, P.

doi:10.1088/0953-8984/18/35/014

Cited by 13 publications

(8 citation statements)

References 33 publications

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“…The appearance of the AFM phase is due to the segregation of the antiferromagnetic material NiO. This behavior of the LSMO/NiO composite was reported by Eshraghi et al (2006) [28]. In addition the values of T N of NiO close to the former study [29].…”

Section: Magnetizationsupporting

confidence: 80%

The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

Ahmed

Mohamed

et al. 2016

Low Temperature Physics

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This investigation is mainly concerned with the effect of annealing temperature (600, 700, 800 and 900 °C) in air for (La 0.7 Ba 0.3 MnO 3 ) 1-x /(NiO) x with x = 0 and x = 0.10 samples. It was shown that the annealing temperature does not affect the structure and parameters of rhombohedral lattice of the samples. However, it is observed that the annealing treatment has a notable effect on the electrical resistivity and the metal-semiconductor transition temperature T ms . Temperature dependent magnetization measurements showed a decrease in Curie temperature T C with annealing temperature. In the same time, annealing process decreases the magnetoresistance of La 0.7 Ba 0.3 MnO 3 , in contrast to (La 0.7 The magnetoresistive material was mixed with an insulator material to enhance the extrinsic CMR that depending on grain boundaries [6] and spin tunneling [7], that CMR may increase under low magnetic fields known as low field magnetoresistance (LFMR). The importance of LFMR refers to use low magnetic field to get high values of MR what is making it useful for applications. This LFMR can be affected by other several factors; one of them is annealing temperature that can affect the grain size and hence the physical properties including LFMR. An annealing effect has a little attention in this direction, especially in LBMO/insulator. Therefore in this work the effects of annealing temperature on the electrical, magnetic, magnetoresistance and thermoelectric properties of La 0.7 Ba 0.3 MnO 3 (LBMO) and (La 0.7 Ba 0.3 MnO 3 ) 0.9 /(NiO) 0.1 (LBMO/NiO) are examined. Experimental(La 0.7 Ba 0.3 MnO 3 ) 1-x /(NiO) x ceramic samples were prepared by the conventional solid state reaction method (x = = 0.0 & 0.10). La 2 O 3 , BaCO 3 and MnCO 3 raw materials were mixed in stoichiometric proportions, ground, pelletized and calcined at 900 °C for 24 h. It was reground again and pelletized and then sintered at 1100 °C for 24 h. NiO insulator was added in stoichiometric portions to the sintered La 0.7 Ba 0.3 MnO 3 compound and lightly ground, then pressed and put in 1000 °C for 24 h. The composites of LBMO and LBMO/NiO annealed for 2 h at 600, 700, 800 and 900 °C. Electrical resistivity was measured by van der Pauw technique in the presence and absence of 0.6 T magnetic field. Samples were examined by x ray, using Brucker (Axs-D& Advance) powder diffractometer at room temperature with Cu (K α ) radiation (λ = 1.5406 Å). The microstructure was investigated by Jeol JSM-6610LV

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Section: Magnetizationsupporting

confidence: 80%

The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

Ahmed

Mohamed

et al. 2016

Low Temperature Physics

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“…The Curie temperature shift was a much lower temperature compared to the pure LSMO films. It should be noted that the small grain size of LSMO, magnetic interaction at the interface between the neighboring grain boundaries, as well as the partial substitution of Ni ion for the Mn ion can explain the decrease of [6]. It is, in fact, found experimentally that the Ni-O-Mn FM interaction at the interface between LSMO and NiO weakens the double exchange interaction significantly [15], [16].…”

Section: Resultsmentioning

confidence: 93%

Exchange Bias Effect and Magnetic Properties in ${\hbox{La}}_{0.7}{\hbox{Sr}}_{0.3}{\hbox{MnO}}_{3}\hbox{-}{\hbox{NiO}}$ Nanocomposite Films

et al. 2014

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The magnetic exchange coupling effect has been investigated in La Sr MnO (LSMO)-NiO nanocomposite films prepared by pulsed laser deposition on SrTiO (001) and (110) single crystal substrates. The films show an enhanced coercivity field Oe compared with the same thickness single pure LSMO thin film. The composite films exhibit a large exchange bias field Oe after applying a 4000 Oe field cooling. The values of the exchange bias field decrease with increasing temperature and become zero at about 45 K, which corresponds to the conventional exchange bias blocking temperature ( ), regardless of epitaxial growth directions on (001) or (110) SrTiO substrates. We speculate that there may be magnetic interaction at the NiO and LSMO boundaries or charge transfer between the Ni and Mn ions, resulting in the formation of ferromagnetic interaction at the interface. The Curie temperature decreased from 340 K of the LSMO single film to 200 K of the nanocomposite film. The results demonstrate that the magnetic state of the composite film is directly related to the Mn-O-Mn and Mn-O-Ni spin interaction energy. In addition to this, the Mn-O-Ni at the boundary may also form the magnetic region that pins the ferromagnetic LSMO phase. Index Terms-Exchange bias (EB), magnetic transport properties, pulse laser deposition (PLD).

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“…As discussed in literature [32,33], there are two kinds of conduction channels, connected in parallel in the polycrystalline manganites. One is related to intragrain and the second one to intergrain hopping of the conduction electron between the neighboring sites.…”

Section: Electrical Propertiesmentioning

confidence: 99%

Effects of pH and sintering temperature on the synthesis and electrical properties of the bilayered LaSr2Mn2O7 manganite prepared by the sol–gel process

2012

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The bilayered LaSr 2 Mn 2 O 7 manganite was synthesized by the sol-gel process at different pH values (3.5, 7, and 9.5) and different sintering temperatures (1553, 1623, and 1723 K) to investigate the effects of growth conditions upon the structural and electrical properties of the samples under investigation. X-Ray diffraction and FT-IR spectroscopy techniques confirm the phase formation for all samples. However, samples sintered at 1553, 1623, and 1723 K, and formed at pH = 7 are single phased having a tetragonal structure. Study of these single-phased samples indicates that with increase in the sintering temperature from 1553 to 1723 K, the average grain size increases from *200 to *1000 nm. To investigate the influence of grain size on the conduction mechanism, resistivity of the samples was measured as a function of temperature. The data obtained was analyzed by the adiabatic small polaron hopping model. These analyses show the influence of grain size on the parameters obtained by fitting the data by the above models.

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Structural, magnetic and transport properties of La_0.8Sr_0.2MnO₃/xNiO composites

Cited by 13 publications

References 33 publications

The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

The annealing influence onto the electrical and magnetic behavior of magnetoresistive/insulator system

Exchange Bias Effect and Magnetic Properties in ${\hbox{La}}_{0.7}{\hbox{Sr}}_{0.3}{\hbox{MnO}}_{3}\hbox{-}{\hbox{NiO}}$ Nanocomposite Films

Effects of pH and sintering temperature on the synthesis and electrical properties of the bilayered LaSr2Mn2O7 manganite prepared by the sol–gel process

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