Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

Abstract

La 0.7 Sr 0.3 MnO 3 (LSMO) and La 0. 7 Ba 0.3 MnO 3 (LBMO) Polycrystalline manganite nanoparticles were prepared by combustion method using glycine fuel. The ignition process was done at 360 °C and 330 °C for LSMO and LBMO, respectively. Both of the samples have rhombohedral structure using XRD analysis. The reduction is observed in electrical resistivity when external magnetic field is applied during the decrease in temperature from 300 to 89 °K, which is due to the tunneling between particles. The magnetoresistance (MR) of samples was measured in this range of temperature in both the presence and absence of a magnetic field of about 10 kG. The colossal role of a kind of extrinsic MR which is 19% and 22% for LSMO and LBMO, respectively, has been investigated in this research. The metal-insulator transition temperature of 200 °K is recorded for LBMO.

Mechanochemical Synthesis of Soft Ferromagnetic Perovskite Lanthanum Strontium Manganite (La0.6Sr0.4MnO3)

“…The obtained values of room temperature resistivity and magnetoresistance are in accepted agreement with previously published data for perovskite phase, with close compositions. The value of MR for nanogranular manganite compounds is expected, as was shown in previously published data, 11,45,48 to increase with the decrease of temperature, which makes the La 0.6 Sr 0.4 MnO 3 sample (prepared in the present work) a good candidate for practical applications related to the magneto-conduction.…”

“…6 The appearance of ferromagnetic ordering is attributed to the existence of Zener's double exchange interaction between Mn 3+ and Mn 4+ ions via the conduction electrons. [7][8][9] The discovery of some interesting effects such as the colossal magnetoresistance effect 10,11 and magnetocaloric effect 1,[12][13][14] in some intermediate concentrations of doping in La 1−x A x MnO 3 compounds has made these compounds very promising and attractive from the fundamental research and from the practical points of view.…”

“…Large number of research articles was devoted (and is still devoted) to the study of strontium doped lanthanum manganite La 1−x Sr x MnO 3 compounds (simply LSMO) due to the appearance of ferromagnetic ordering with Curie temperature T c slightly higher than room temperature for Sr concentrations in the interval from x = 0.2 to x = 0.5 (with maximum T c for x about 0.4) 2 and the discovery of colossal magnetoresistance and magnetocaloric effects at the same interval of Sr concentration. 11,15,16 A composition of La 0.6 Sr 0.4 MnO 3 (which lies inside this interval) was chosen to be the subject of this research work.…”

Incorporation of Bulk Proton Carriers in Cubic Perovskite Manganite Driven by Interplays of Oxygen and Manganese Redox

“…The LSM specimens thus prepared show only a single intensive peak in the 2θ range of 31–34°, so that these would be identical to the cubic or orthorhombic structure rather than the rhombohedral one involving two distinct peaks in the 2θ region (Figure b). Rietveld refinement was performed for the LSM series prepared at 700 °C with the cubic ( Pm 3̅ m ), orthorhombic ( Pnma ), and rhombohedral ( R 3̅ c ) LaMnO 3 structure model. − For these, the best fitting is obtained with the cubic structure model with minimized Rietveld parameter ( R wp ) values (Figures S1 and S2, and Table S1), confirming that the LSM prepared at 700 °C is analogous to the cubic perovskite phase. These are denoted hereafter with the prefix of “C-” (e.g.…”

Magnetic Properties of La0.9A0.1MnO3 (A: Li, Na, K) Nanopowders and Nanoceramics

“…The discovery of the colossal magnetoresistance (CMR) effect in alkaline ion (A)-doped rare earth (RE) perovskite-type manganites with a composition of RE 1−x A x MnO 3 , has attracted ample attention in recent years [1][2][3]. The studies on such manganites have revealed that the CMR effect is attributed to the presence of Mn 3+ and Mn 4+ ions together with the site-site double-exchange (DE) mechanism [4].…”