Far-infrared and dc-Magnetotransport of CaMnO3 CaRuO3 Superlattices

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review B

OSTI ID:1042814

Yordanov, P. ^[1]; Boris, A. V. ^[1]; Freeland, J. W. ^[2]; Kavich, J. J. ^[3]; Chakhalian, J. ^[4]; Lee, Ho Nyung ^[5]; Keimer, Bernhard ^[1]

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1. Max-Planck-Institut fur Feskorperforschung, Stuttgart, Germany
2. Argonne National Laboratory (ANL)
3. University of Illinois, Chicago
4. University of Arkansas
5. ORNL

We report temperature- and magnetic-field-dependent measurements of the dc resistivity and the far-infrared reflectivity (FIR) (photon energies {h_bar}{omega} = 50-700 cm{sup -1}) of superlattices comprising ten consecutive unit cells of the antiferromagnetic insulator CaMnO{sub 3}, and four to ten unit cells of the correlated paramagnetic metal CaRuO{sub 3}. Below the Neel temperature of CaMnO{sub 3}, the dc resistivity exhibits a logarithmic divergence upon cooling, which is associated with a large negative, isotropic magnetoresistance. The {omega} {yields} 0 extrapolation of the resistivity extracted from the FIR reflectivity, on the other hand, shows a much weaker temperature and field dependence. We attribute this behavior to scattering of itinerant charge carriers in CaRuO{sub 3} from sparse, spatially isolated magnetic defects at the CaMnO{sub 3}-CaRuO{sub 3} interfaces. This field-tunable 'transport bottleneck' effect may prove useful for functional metal-oxide devices.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1042814
• Journal Information: Physical Review B, Vol. 84, Issue 4; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHARGE CARRIERS
DEFECTS
EXTRAPOLATION
FUNCTIONALS
MAGNETORESISTANCE
NEEL TEMPERATURE
REFLECTIVITY
SCATTERING
SUPERLATTICES
TRANSPORT