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

Journal Article · Sat Feb 01 00:00:00 EST 2014 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2013.10.016· OSTI ID:22345199

Ivanov, S. A. ^[1]; Nordblad, P. ^[2]; Ritter, C. ^[3]; Tellgren, R. ^[4]; Golubko, N.; Mosunov, A.; Politova, E. D. ^[1]; Weil, M. ^[5]

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1. Center of Materials Science, Karpov Institute of Physical Chemistry, Moscow 105064 (Russian Federation)
2. Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden)
3. Institute Laue-Langevin, Grenoble (France)
4. Department of Chemistry, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden)
5. Institute for Chemical Technologies and Analytics, Vienna University of Technology, A-1060 Vienna (Austria)

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 susceptibility 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.

• OSTI ID: 22345199
• Journal Information: Materials Research Bulletin, Vol. 50; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

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