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Title: Heat capacity and neutron diffraction studies on the frustrated magnetic Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1] solid solution

Journal Article · · Journal of Solid State Chemistry
 [1]; ;  [2];  [3];  [1]
  1. Departamento de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, 48080 Bilbao (Spain)
  2. CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain)
  3. Institut Laue-Langevin, BP 156X, F-38042 Grenoble Cedex (France)

The Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1] solid solution exhibits a complex magnetic behaviour due to the bond-frustration in its magnetic structure. Heat capacity measurements of the (x=0.1-0.5) phases show a three-dimensional magnetic ordering ({lambda} anomaly) that shifts to lower temperatures and becomes broader as the AsO{sub 4}{sup 3-} content increases. For x=0.75, no significant feature was observed whereas for higher arsenate ion content, x=0.9 and 1, a small maximum was detected. The magnetic structures of solid solution are consistent with the existence of predominant antiferromagnetic superexchange interactions through the |OH| and |XO{sub 4}| (X=P and As) groups between the Co{sup +2} ions. The substitution of PO{sub 4}{sup 3-} by AsO{sub 4}{sup 3-} anions by more than 90% substantially modifies the magnetic exchange pathways in the solid solution, leading to an incommensurate antiferromagnetic structure in Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [x=0.9 and 1] phases. - Graphical abstract: Magnetic structures of Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1]. The ordering of the magnetic moments of Co{sup 2+} is in c direction for the two crystallographic positions (dimers and chains) in all compounds. The unit cell is surrounded by a red line. Highlights: Black-Right-Pointing-Pointer Synthesis of a new adamite-type compounds, Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} (0.1, 0.25, 0.5, 0.75, 0.9) phases. Black-Right-Pointing-Pointer Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} (0-1) solid solution; magnetic frustrated system. Black-Right-Pointing-Pointer High resolution neutron powder diffraction to determine the crystal structures. Black-Right-Pointing-Pointer Incommensurate magnetic structures at low temperature. Black-Right-Pointing-Pointer Magnetostructural correlations in cobalt-based Co{sub 2}(OH)XO{sub 4} (X=P and As) insulation compounds.

OSTI ID:
22012081
Journal Information:
Journal of Solid State Chemistry, Vol. . 188; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
Country of Publication:
United States
Language:
English