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Tunneling Magnetoresistance (tunneling + magnetoresistance)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Physics and Astronomy	50%

Selected Abstracts

Crossing an Interface: Ferroelectric Control of Tunnel Currents in Magnetic Complex Oxide Heterostructures

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2010
Michael Hambe
Abstract Experimental results on entirely complex oxide ferromagnetic/ferroelectric/ferromagnetic tunnel junctions are presented in which the tunneling magnetoresistance is modified by applying low electric field pulses to the junctions. The experiments indicate that ionic displacements associated with the polarization reversal in the ferroelectric barrier affect the complex band structure at ferromagnetic,ferroelectric interfaces. The results are discussed in the framework of the theoretically predicted magnetoelectric interface effect and may lead to novel multistate memory devices. [source]

Application of Nanostructured ASP Precursors for Processing CaCuMn6O12 Colossal Magnetoresistance Ceramics

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 4 2006
Anastasia E. Chekanova
Nanostructured precursors prepared by ultrasonic aerosol spray pyrolisys at 750,950°C in air were applied for the first time to obtain Ca(Cu,Mn)7O12 colossal magnetoresistance ceramics with a unique submicron necked-grain microstructure. It was observed that a high contribution of intergrain tunneling magnetoresistance results in a 10,20% difference in functional properties as dependent on morphological features of hollow precursor microspheres ASP processed at a given temperature. [source]

Magnetic and transport properties of the Co-doped manganite La0.7Sr0.3Mn1,xCoxO3 (0 , x , 0.5)

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2005
B. C. Zhao
Abstract The effect of Co doping on the magnetic and transport properties of La0.7Sr0.3Mn1,xCoxO3 (0 , x , 0.5) is investigated. The Co doping at Mn sites dilutes the double-exchange interaction between Mn3+ and Mn4+ ions and changes the long-range ferromagnetic (FM) order of La0.7Sr0.3MnO3 (LSMO) to the spin glass (SG) or cluster glass (CG) state for samples with x , 0.1. For x , 0.3, the paramagnetic (PM) metal to FM metal transition of LSMO disappears and the temperature dependence of resistivity ,(T) follows semiconducting behavior in the whole measured temperature region with the resistivity increasing by orders of magnitude. An interesting result is that ,(T) exhibits an obvious anomaly at T* , 100 K, which is ascribed to the spin-state transition of Co ions. For samples with x = 0.1 and 0.3, magnetoresistance (MR) effects are markedly enhanced in the low-temperature region compared with undoped LSMO, which is suggested to originate from the appearance of spin-dependent tunneling magnetoresistance. However, for samples with x = 0.5, the MR effect is suppressed over the entire temperature region measured and an obvious exchange anisotropy phenomenon, characterized by the shift of the hysteresis loop, is also observed, which is ascribed to the marked increase of the antiferromagnetic insulating phase. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Co2MnSi as full Heusler alloy ferromagnetic electrode in magnetic tunneling junctions

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2006
G. Reiss
Abstract The discoveries of antiferromagnetic coupling in Fe/Cr multilayers by Grünberg, the Giant MagnetoResistance by Fert and Grünberg and a large tunneling magnetoresistance at room temperature by Moodera have triggered enormous research on magnetic thin films and magnetoelectronic devices. Large opportunities are especially opened by the spin dependent tunneling resistance, where a strong dependence of the tunneling current on an external magnetic field can be found. In order to obtain large magnetoresistance effects, materials with strongly spin polarized electron gas around the Fermi level have to be found. New materials with potentially 100% spin polarization will be discussed using the example of the full Heusler compound Co2MnSi. First, experimental aspects of the integration of this alloy in magnetic tunneling junctions will be addressed. With these junctions, we obtain up to 100% TMR at low temperature. The current status of this research will then be summarized with special regard to the complex diffusion mechanisms occurring in these devices and to the properties of the interfaces between the Heusler material and the insulator. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]