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Title: Positive magnetoresistance of single-crystal bilayer manganites (La{sub 1−z}Nd{sub z}){sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} (z = 0, 0.1)

We investigate magnetoresistance, ρ{sub c}, of single-crystal bilayer lanthanum manganites (La{sub 1−z}Nd{sub z}){sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} (z = 0 and 0.1) at a transport current flowing along the crystal c axis and in external magnetic fields applied parallel to the crystal c axis or ab plane. It is demonstrated that the La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} manganite exhibits the positive magnetoresistance effect in the magnetic field applied in the ab sample plane at the temperatures T < 60 K, along with the negative magnetoresistance typical of all the substituted lanthanum manganites. In the (La{sub 0.9}Nd{sub 0.1}){sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} sample, the positive magnetoresistance effect is observed at temperatures of 60–80 K in an applied field parallel to the c axis. The mechanism of this effect is shown to be fundamentally different from the colossal magnetoresistance effect typical of lanthanum manganites. The positive magnetoresistance originates from spin-dependent tunneling of carriers between the manganese-oxygen bilayers and can be explained by features of the magnetic structure of the investigated compounds.
Authors:
; ; ; ;  [1] ;  [1] ;  [2]
  1. Kirensky Institute of Physics, Akademgorodok 50, bld. 38, Krasnoyarsk 660036 (Russian Federation)
  2. (Russian Federation)
Publication Date:
OSTI Identifier:
22402922
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 16; 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; CHARGE CARRIERS; CONCENTRATION RATIO; ELECTRIC CURRENTS; LANTHANUM COMPOUNDS; LAYERS; MAGNETIC FIELDS; MAGNETORESISTANCE; MANGANATES; MANGANESE; MONOCRYSTALS; NEODYMIUM COMPOUNDS; OXYGEN; SPIN; STRONTIUM COMPOUNDS; TUNNEL EFFECT