Colossal magnetoresistance

About: Colossal magnetoresistance is a research topic. Over the lifetime, 3658 publications have been published within this topic receiving 130104 citations.

Low field magnetotransport properties of (La0.7Sr0.3MnO3)0.5:(ZnO)0.5 nanocomposite films

Abstract: (La0.7Sr0.3MnO3)0.5:(ZnO)0.5 nanocomposite thin films were deposited on c-cut sapphire substrates via pulsed laser deposition. The as-grown films were composed of fine grains of 20–50nm size. The epitaxial orientation relationships between the La0.7Sr0.3MnO3 (LSMO) and the sapphire was (111)LSMO∕∕(0003)Al2O3 and ⟨112¯⟩LSMO∕∕⟨101¯0⟩Al2O3. A low field magnetoresistance (LFMR) of ∼12% was achieved at an external magnetic field of H=1T at 77K, possibly due to enhanced grain boundary effects. The postannealed film had columnar structures with well-crystallized large grains (∼200nm), and showed a low resistivity and consequently negligible LFMR similar to that of single crystal LSMO.

Nanoscale Electronic Inhomogeneity in In2Se3 Nanoribbons Revealed by Microwave Impedance Microscopy

Abstract: Driven by interactions due to the charge, spin, orbital, and lattice degrees of freedom, nanoscale inhomogeneity has emerged as a new theme for materials with novel properties near multiphase boundaries. As vividly demonstrated in complex metal oxides and chalcogenides, these microscopic phases are of great scientific and technological importance for research in high-temperature superconductors, colossal magnetoresistance effect, phase-change memories, and domain switching operations. Direct imaging on dielectric properties of these local phases, however, presents a big challenge for existing scanning probe techniques. Here, we report the observation of electronic inhomogeneity in indium selenide (In2Se3) nanoribbons by near-field scanning microwave impedance microscopy. Multiple phases with local resistivity spanning six orders of magnitude are identified as the coexistence of superlattice, simple hexagonal lattice and amorphous structures with 100nm inhomogeneous length scale, consistent with high-resolution transmission electron microscope studies. The atomic-force-microscope-compatible microwave probe is able to perform quantitative sub-surface electronic study in a noninvasive manner. Finally, the phase change memory function in In2Se3 nanoribbon devices can be locally recorded with big signal of opposite signs.

Neutron diffraction evidence for a new ferromagnetic phase in Cr doped Pr0.5Ca0.5MnO3

Abstract: Cr doping in Pr0.5Ca0.5MnO3 is known to destroy the low-temperature antiferromagnetic charge-ordered state and to induce a ferromagnetic component as well as colossal magnetoresistance properties. Effects of Cr doping on the magnetic and nuclear structures are studied here by neutron diffraction for Pr0.5Ca0.5Mn0.95Cr0.05O3. It is shown that, at low temperature, the strongly distorted charge ordered structure usually observed in Pr0.5Ca0.5MnO3 is replaced by a ferromagnetic phase in which the basal-plane distortion of the MnO6 octahedra has disappeared, in agreement with the restoration of the double–exchange interactions.

Colossal magnetoresistance in epitaxial $La_(_1_-_x_-_y_)$$Na_y$$MnO_3$ thin film

Abstract: We have synthesized La0.83Na0.11MnO2.93 by heating La2O3 and MnCO3 in NaCl melt at 900 degrees C. The exact composition was arrived by analyzing each ion by an independent chemical method. The compound crystallized in a rhombohedral structure and showed an insulator-to-metal transition at 290 K. Epitaxial thin films were fabricated on LaAlO3 (100) using a pulsed laser deposition technique. The film also showed an insulator-to-metal transition at 290 K. Magnetoresistance [Delta R/R-0=(R-H-R-0)/R-0] was - 71% near the insulator-to-metal transition temperature of 290 K at 6 T magnetic field.