Temperature dependence of anisotropic magnetoresistance in antiferromagnetic Sr{sub 2}IrO{sub 4}

Journal Article · Thu May 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4913300· OSTI ID:22403020

Wang, C.; Seinige, H.; Cao, G. ^[1]; Zhou, J. -S.; Goodenough, J. B. ^[2]

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1. Center for Advanced Materials, University of Kentucky, Lexington, Kentucky 40506 (United States)
2. Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

Temperature-dependent magnetotransport properties of the antiferromagnetic semiconductor Sr{sub 2}IrO{sub 4} are investigated with point-contact devices. The point-contact technique allows to probe very small volumes and, therefore, to look for electronic transport on a microscopic scale. Point-contact measurements with single crystals of Sr{sub 2}IrO{sub 4} were intended to see whether the additional local resistance associated with a small contact area between a sharpened Cu tip and the antiferromagnet shows magnetoresistance (MR) such as that seen in bulk crystals. Point-contact measurements at liquid nitrogen temperature revealed large MRs (up to 28%) for modest magnetic fields (250 mT) applied within an IrO{sub 2} (ab) plane with angular dependence showing a crossover from four-fold to two-fold symmetry with an increasing magnetic field. Point contact measurement exhibits distinctive anisotropic magnetoresistance (AMR) in comparison to a bulk experiment, imposing intriguing questions about the mechanism of AMR in this material. Temperature-dependent MR measurements show that the MR falls to zero at the Neel temperature, but the temperature dependence of the MR ratio differs qualitatively from that of the resistivity. This AMR study helps to unveil the entanglement between electronic transport and magnetism in Sr{sub 2}IrO{sub 4} while the observed magnetoresistive phenomena can be potentially used to sense the antiferromagnetic order parameter in spintronic applications.

• OSTI ID: 22403020
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
ANTIFERROMAGNETISM
COMPARATIVE EVALUATIONS
ELECTRIC CONTACTS
IRIDIUM OXIDES
MAGNETIC FIELDS
MAGNETORESISTANCE
MONOCRYSTALS
NEEL TEMPERATURE
ORDER PARAMETERS
SEMICONDUCTOR MATERIALS
STRONTIUM COMPOUNDS
TEMPERATURE DEPENDENCE