Topic
Colossal magnetoresistance
About: Colossal magnetoresistance is a research topic. Over the lifetime, 3658 publications have been published within this topic receiving 130104 citations.
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TL;DR: In this paper, a reversible control of ferromagnetic phase transition in manganite films through ionic liquid gating is reported, where the formation and annihilation of an insulating and magnetically hard phase in the magnetically soft matrix, which randomly nucleates and grows across the film instead of initiating at the surface and spreading to the bottom, is directly observed.
Abstract: The electronic phase transition has been considered as a dominant factor in the phenomena of colossal magnetoresistance, metal-insulator transition, and exchange bias in correlated electron systems. However, the effective manipulation of the electronic phase transition has remained a challenging issue. Here, the reversible control of ferromagnetic phase transition in manganite films through ionic liquid gating is reported. Under different gate voltages, the formation and annihilation of an insulating and magnetically hard phase in the magnetically soft matrix, which randomly nucleates and grows across the film instead of initiating at the surface and spreading to the bottom, is directly observed. This discovery provides a conceptually novel vision for the electric-field tuning of phase transition in correlated oxides. In addition to its fundamental significance, the realization of a reversible metal-insulator transition in colossal magnetoresistance materials will also further the development of four-state memories, which can be manipulated by a combination of electrode gating and the application of a magnetic field.
80 citations
TL;DR: In this paper, it was observed that crystallisation nature depends on y = (La + A)/Mn ratio in a melt and that stable growth of undoped, Sr substituted (up to x = 0.3) and Ca substituted (x < 0.5°) single crystals with mosaicity not more than 0.9-0.95° were produced.
80 citations
TL;DR: In this paper, the crystal structure and magnetoresistance of La1-xNaxMnO3 were investigated and it was shown that Na doping tends to drive the system from a regime characterized by strong Hund coupling and strong electron-phonon coupling to one characterized by weak Hund coupled and weak electron-on coupling.
Abstract: The crystal structure and magnetoresistance of are investigated. La1-xNaxMnO3 crystallizes in a rhombohedrally distorted perovskite structure and exhibits a sharp ferromagnetic transition as well as a negative magnetoresistance at around room temperature. On the basis of alternating-current susceptibility and resistivity measurements as well as a comparison with La1-xNaxMnO3 compounds, it is proposed that Na doping tends to drive the system from a regime characterized by strong Hund coupling and strong electron-phonon coupling to one characterized by weak Hund coupling and weak electron-phonon coupling.
80 citations
TL;DR: A Raman scattering study of the lattice dynamics in superlattices of the high-temperature superconductor YBa(2)Cu(3)O(7) (YBCO) and the colossal-magnetoresistance compound La(2/3)Ca(1/3]MnO( 3) that suggests a new approach to this problem.
Abstract: The interaction between electrons and phonons is important for many materials properties. The finding that phonon modes of a superconducting thin film can influence the properties of an adjacent normal conductor, even over comparatively long distances, suggests new ways of controlling electron–phonon interactions. The electron–phonon interaction is of central importance for the electrical and thermal properties of solids, and its influence on superconductivity, colossal magnetoresistance and other many-body phenomena in correlated-electron materials is the subject of intense research at present. However, the non-local nature of the interactions between valence electrons and lattice ions, often compounded by a plethora of vibrational modes, presents formidable challenges for attempts to experimentally control and theoretically describe the physical properties of complex materials. Here we report a Raman scattering study of the lattice dynamics in superlattices of the high-temperature superconductor YBa2Cu3O7 (YBCO) and the colossal-magnetoresistance compound La2/3Ca1/3MnO3 that suggests a new approach to this problem. We find that a rotational mode of the MnO6 octahedra in La2/3Ca1/3MnO3 experiences pronounced superconductivity-induced line-shape anomalies, which scale linearly with the thickness of the YBCO layers over a remarkably long range of several tens of nanometres. The transfer of the electron–phonon coupling between superlattice layers can be understood as a consequence of long-range Coulomb forces in conjunction with an orbital reconstruction at the interface. The superlattice geometry thus provides new opportunities for controlled modification of the electron–phonon interaction in complex materials.
80 citations
TL;DR: In this article, a quasi-one-dimensional model of spin transport in heterogeneous media based on the Boltzmann equation is presented in order to define the basic properties characterizing perpendicular spin transport.
Abstract: A quasi one-dimensional model of spin transport in heterogeneous media based on the Boltzmann equation is presented in order to define the basic properties characterizing perpendicular spin transport in nanostructures. Experimental results are reviewed, first on the giant magnetoresistance of magnetic multilayers: spin dependent scattering in bulk and at interfaces, spin-diffusion length in the ferromagnetic layers and in the non-magnetic spacers. The observations of magnetoresistance associated with spin-scattering at Bloch walls are summarized. The junction magnetoresistance of ferromagnetic-insulator-ferromagnetic structures are reviewed, including the tunnel junctions produced with materials which present colossal magnetoresistance. An outlook on possible devices and novel structures is given.
80 citations