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Abstract Perovskite Lanthanum strontium manganite (LSMO) has been analyzed as a proficient hyperthermia mediator for a couple of decades. In the present study ( La 1 − x Sr x MnO 3) with Sr concentration (x = 0.27 & 0.33) are coated with biocompatible polymer Sodium Oleate (SO). SO coating is done by adopting novel routes. One of them has been applied for ferrites formerly and is being successfully done with LSMOs in the present task. The other methods of coating are done by choosing different concentrations of the polymer as well as adjusting different parameters related to it. The objective is to evaluate a detailed comparative study of two different LSMOs' series with the same coating polymer in order to understand their Hyperthermia efficacy. LSMOs are synthesized by Citrate-gel route having an approximate size of ∼17 nm as revealed by XRD and after surface functionalization with the polymer, are characterized by a number of analytical procedures to examine their different properties. The polymers reveal an efficient surface attachment with NPs as disclosed by FTIR. The coated NPs exhibit very narrow hysteresis loop and appreciable saturation magnetization at room temperature when subjected to VSM. TGA and DTA analysis show relative amounts of polymer bonded to the LSMOs surface and subsequent decomposition mechanisms. The magnetic induction heating studies by employing radio frequency alternating field display adequate response of these prepared NPs in Hyperthermia range (40–60 °C). These coated NPs show an appreciable approach towards efficient induction heating when dispersed in normal Saline for the first time as a carrier medium proving to be an effective ferrofluid. Graphical abstract Image 1 Highlights • Lanthanum strontium manganite (La 1-x Sr x MnO 3) with Sr concentration (x = 0.27 & 0.33) were coated with biocompatible polymer Sodium Oleate (SO). • LSMOs were synthesized by Citrate-gel route having an approximate size of ∼ 17 nm revealed by XRD and after surface functionalization with polymer, were characterized by a number of analytical procedures to examine their different properties. • The polymers had an efficient surface attachment with NPs as disclosed by FTIR. The coated NPs exhibited very narrow hysteresis loop and appreciable saturation magnetization at room temperature when subjected to VSM. • TGA and DTA analysis showed relative amounts of polymers bonded to the LSMOs surface and subsequent decomposition mechanisms. The magnetic induction heating studies by employing radio frequency alternating field displayed adequate response of these prepared NPs in Hyperthermia range (40–60 °C). • These coated NPs showed an appreciable approach towards efficient induction heating when dispersed in normal Saline as a carrier medium proving to be an effective ferrofluid. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the structural, magnetic, and dielectric properties of the compounds La BiSrMnGaO ( x = 0 and 0.06) synthesized with the ceramic method. The structural studies of the compounds showed their indexation in the rhombohedral structure with the R-3C space group. The M( T) investigations under an applied magnetic field of 0.05 T presented a single ferromagnetic-paramagnetic phase transition around the Curie temperature T . Gallium doping with non-magnetic coupling between Ga −O −Gareduces the Curie temperature to lower values: T = 360 K for x = 0 and T = 350 K for x = 0.06. The impedance plot at room temperature ( T = 330 K) appeared as uncompleted semicircular arcs off-centered on the real axis, indicating that the electrical conduction arises from the grain boundaries. The electrical equivalent circuit has been proposed as a parallel combination of grain boundary resistance R and constant phase element impedance (Z) to explain the impedance results. The study of the conductivity with respect to frequency at T = 303 K displayed the reduction of the electron hopping (coulombic interactions) with gallium doping. [ABSTRACT FROM AUTHOR]

We investigate the suitability of an epitaxial CaTiO3 buffer layer deposited onto (100) Si by reactive molecular-beam epitaxy (MBE) for the epitaxial integration of the colossal magnetoresistive material La0.7Sr0.3MnO3 with silicon. The magnetic and electrical properties of La0.7Sr0.3MnO3 films deposited by MBE on CaTiO3-buffered silicon (CaTiO3/Si) are compared with those deposited on SrTiO3-buffered silicon (SrTiO3/Si). In addition to possessing a higher Curie temperature and a higher metal-to-insulator transition temperature, the electrical resistivity and 1/f noise level at 300 K are reduced by a factor of two in the heterostructure with the CaTiO3 buffer layer. These results are relevant to device applications of La0.7Sr0.3MnO3 thin films on silicon substrates. [ABSTRACT FROM AUTHOR]

La0.67Sr0.33MnO3 thin films exhibiting a highly (001)-plane oriented and polycrystalline structure with a variable amount of (011)-textured crystallites have been grown in situ by RF magnetron sputtering on crystalline MgO(001) substrates by changing deposition temperature from 550 to 800 °C. Competing contribution of grains and grain boundaries to resistivity and magnetoresistance of the films has been investigated at T = (78-330) K. A model based on two parallel channels of current flow across grain boundaries has been applied to explain coexistence of low (LFMR) and high field (HFMR) magnetoresistance effects in the polycrystalline films at low temperatures. The LFMR effect has been understood assuming tunnelling of spin-polarized carriers via magnetic field-driven tunnelling barriers formed naturally between neighbouring misoriented grains. Meanwhile, the HFMR phenomenon has been associated with magnetic field-dependent hopping of carriers via the intergrain regions with reduced carrier density. Importance of the phase separation phenomenon on possible inhomogeneity of the material at grain boundaries has been discussed. [ABSTRACT FROM AUTHOR]

Influence of BTO phase on structural and electric properties of LSMO phase has been investigated by synthesizing a manganite matrix-based composite series (1 − x )La 0.67 Sr 0.33 MnO 3 + ( x )BaTiO 3 with x = 0.0, 0.05, 0.10, 0.15, 0.20, and 0.25 (abbreviated as LSMO–BTO) by solid-state reaction method. Rietveld refined X-ray diffraction (XRD) data infers that manganite LSMO compound possess a rhombohedrally-distorted structure (space group R 3 c ), while to that BTO compound crystallizes in tetragonal structure (space group P 4 mm ). The structural parameters and the reliability factors for the LSMO–BTO composite ceramics were successfully determined by the Rietveld refinement. The resistivity measurements infer that the metal–insulator transition temperature was shifted towards lower temperature as well as resistivity increases with increasing BTO content in LSMO–BTO composites. Measurement of resistivity of these samples shows more prominent extrinsic metal insulator (EMI) transition at temperature T EMI . At H = 8 T, the magnetoresistance is enhanced in the wide temperature ranges due to introduction of BaTiO 3 content in La 0.67 Sr 0.33 MnO 3 which could be explained by enhanced spin polarized tunneling. [ABSTRACT FROM AUTHOR]

La0.7Sr0.3MnO3 (LSMO) film exhibits certain unique properties which make it an ideal material for heterostructure-based multifunctional devices. In this paper, La0.7Sr0.3MnO3 thin films were grown epitaxially on SrTiO3, LaAlO3(LAO) and (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7(LSAT) substrates, and their structural, electrical, magnetic and optical properties were examined and compared, aiming at revealing and explaining the effects of substrate on fundamental physical properties of LSMO films. Results show that (i) the effects of substrate materials on the electrical conductivity and paramagnetic–ferromagnetic transition temperature of the LSMO films could be ignored, and (ii) the LSMO film on LAO substrate has much higher coercive field and slower photoinduced relaxation process than other samples. This unusual behavior observed in the LSMO film on the LAO substrate could be related to the nature of the LAO substrate itself, on which the LSMO film showed different easy magnetization direction, and the film also exhibited relatively poor crystalline quality due to the twin domain structure of LAO crystal. Our results may help to understand the substrate-related electrical, magnetic and optical properties for perovskite manganite films. [ABSTRACT FROM AUTHOR]