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Title: Chemical pressure effects on structural, dielectric and magnetic properties of solid solutions Mn{sub 3−x}Co{sub x}TeO{sub 6}

Highlights: • Mn{sub 3}TeO{sub 6} and Co{sub 3}TeO{sub 6} are antiferromagnets with corundum related structures. • The structural and magnetic properties of Mn{sub 3−x}Co{sub x}TeO{sub 6} ceramics were investigated. • All compounds adopt the trigonal structure of Mn{sub 3}TeO{sub 6} up to at least x = 2.4. • The antiferromagnetic transition temperature monotonously increases with x. • NPD data evidences the magnetic structure of the Mn{sub 3−x}Co{sub x}TeO{sub 6} ceramics. - Abstract: The effects of Co{sup 2+} doping on the structural, magnetic and dielectric properties of the multiferroic frustrated antiferromagnet Mn{sub 3}TeO{sub 6} have been investigated. Ceramic samples of the solid solution series Mn{sub 3−x}Co{sub x}TeO{sub 6} were prepared by a solid-state reaction route. X-ray and neutron powder diffraction and electron microscopy techniques were combined with calorimetric, dielectric and magnetic measurements to investigate the dependence of the crystal structure and physical properties on temperature and composition. It is shown that the compounds with x ≤ 2.4 adopt the trigonal corundum-related structure of pure Mn{sub 3}TeO{sub 6} (space group R3{sup ¯}) in the temperature range 5–295 K and that the lattice parameters a and c and the unit-cell volume V decrease linearly with increasing Co{sup 2+} concentration. The low-temperature magnetic susceptibilitymore » and heat capacity data evidence the antiferromagnetic ordering of all samples. The Neel temperature linearly increases with Co{sup 2+} concentration x. Curie–Weiss fits of the high temperature susceptibility indicate that the magnetic frustration decreases with x. The derived magnetic structure of Mn{sub 3}TeO{sub 6} can be described as an incommensurately modulated magnetic spin state with k = [0, 0, k{sub z}] and an elliptical spin-spiral order of spins within the chains of MnO{sub 6} octahedra. With increasing Co{sup 2+} concentration the propagation vector k{sub z} changes from 0.453 (x = 0) to 0.516 (x = 2.4). The magnetic anisotropy changes as well, leading to a reorientation of the spiral-basal plane. A possible coexistence of long-range order of electrical dipoles and magnetic moments in Mn{sub 3−x}Co{sub x}TeO{sub 6} is discussed.« less
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [4] ;  [5] ; ; ;  [1] ;  [6]
  1. Center of Materials Science, Karpov Institute of Physical Chemistry, Moscow 105064 (Russian Federation)
  2. (Sweden)
  3. Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden)
  4. Institute Laue-Langevin, Grenoble (France)
  5. Department of Chemistry, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden)
  6. Institute for Chemical Technologies and Analytics, Vienna University of Technology, A-1060 Vienna (Austria)
Publication Date:
OSTI Identifier:
22345199
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 50; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANTIFERROMAGNETISM; CERAMICS; COBALT IONS; CORUNDUM; CRYSTAL STRUCTURE; DIELECTRIC PROPERTIES; ELECTRON MICROSCOPY; LATTICE PARAMETERS; MAGNETIC MATERIALS; MAGNETIC SUSCEPTIBILITY; MANGANESE OXIDES; NEEL TEMPERATURE; NEUTRON DIFFRACTION; SOLID SOLUTIONS; SPACE GROUPS; SPECIFIC HEAT; SPIN; X RADIATION; X-RAY DIFFRACTION