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

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 themore » antiferromagnetic order parameter in spintronic applications.« less
Authors:
; ;  [1] ;  [2] ;  [3] ; ;  [4]
  1. Physics Department, University of Texas at Austin, Austin, Texas 78712 (United States)
  2. (United States)
  3. Center for Advanced Materials, University of Kentucky, Lexington, Kentucky 40506 (United States)
  4. Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)
Publication Date:
OSTI Identifier:
22403020
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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