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Title: The effect of Ca-substitution in La-site on the magnetic properties of La{sub 2}CoMnO{sub 6}

Double perovskite La{sub 2-x}Ca{sub x}CoMnO{sub 6} (x = 0, 0.1, 0.2, 0.5) ceramics samples were synthesized by the standard solid-state reaction method. The crystal structures have been confirmed to be monoclinic perovskite structure with space group of P2{sub 1}/n at room temperature by the powder x-ray diffraction (Cu-Kα). The grains of the samples are relatively dense and distribute in random directions from the scanning electron microscope patterns. Holes are doped into La{sub 2}CoMnO{sub 6} with the substitution of the Ca{sup 2+} ions in La-site, and further lead to the valences of Mn ions and Co ions transforming from Mn{sup 4+} and Co{sup 2+} to Mn{sup 3+} and Co{sup 3+}, respectively. Ferromagnetic coupling of Mn{sup 4+}-O{sup 2–}-Co{sup 2+} and antiferromagnetic coupling of Mn{sup 3+}-O{sup 2–}-Co{sup 3+} are coexistent in La{sub 2-x}Ca{sub x}CoMnO{sub 6} system, which correspond to two transitions existed in field-cooling magnetization versus temperature curves. Curie temperature of La{sub 2-x}Ca{sub x}CoMnO{sub 6} system decreases with the increasing of Ca-substitution amount. The coexistence of different magnetic phases leads to the exchange bias effect.
Authors:
; ; ; ; ; ; ;  [1]
  1. Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China)
Publication Date:
OSTI Identifier:
22308478
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROMAGNETISM; CALCIUM IONS; CERAMICS; COBALT COMPOUNDS; COBALT IONS; CURIE POINT; DOPED MATERIALS; LANTHANUM COMPOUNDS; MAGNETIC PROPERTIES; MAGNETIZATION; MANGANATES; MANGANESE IONS; MONOCLINIC LATTICES; OXYGEN IONS; PEROVSKITE; SCANNING ELECTRON MICROSCOPY; SPACE GROUPS; TEMPERATURE RANGE 0273-0400 K; X-RAY DIFFRACTION