Crystal structure and magnetic properties of Li,Cr-containing molybdates Li{sub 3}Cr(MoO{sub 4}){sub 3}, LiCr(MoO{sub 4}){sub 2} and Li{sub 1.8}Cr{sub 1.2}(MoO{sub 4}){sub 3}

Journal Article · Tue Dec 15 00:00:00 EST 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.09.012· OSTI ID:21372419

Sarapulova, A ^[1]; Mikhailova, D ^[1]; Senyshyn, A ^[2]; Ehrenberg, H ^[1]

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1. Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany)
2. Institute for Materials Science, Darmstadt University for Technology, Petersenstr. 23, D-64287, Darmstadt (Germany)

Single crystals of LiCr(MoO{sub 4}){sub 2}, Li{sub 3}Cr(MoO{sub 4}){sub 3} and Li{sub 1.8}Cr{sub 1.2}(MoO{sub 4}){sub 3} were grown by a flux method during the phase study of the Li{sub 2}MoO{sub 4}-Cr{sub 2}(MoO{sub 4}){sub 3} system at 1023 K. LiCr(MoO{sub 4}){sub 2} and Li{sub 3}Cr(MoO{sub 4}){sub 3} single phases were synthesized by solid-state reactions. Li{sub 3}Cr(MoO{sub 4}){sub 3} adopts the same structure type as Li{sub 3}In(MoO{sub 4}){sub 3} despite the difference in ionic radii of Cr{sup 3+} and In{sup 3+} for octahedral coordination. Li{sub 3}Cr(MoO{sub 4}){sub 3} is paramagnetic down to 7 K and shows a weak ferromagnetic component below this temperature. LiCr(MoO{sub 4}){sub 2} is isostructural with LiAl(MoO{sub 4}){sub 2} and orders antiferromagnetically below 20 K. The magnetic structure of LiCr(MoO{sub 4}){sub 2} was determined from low-temperature neutron diffraction and is based on the propagation vektor k{sup -}>=(1/2 ,1/2 ,0). The ordered magnetic moments were refined to 2.3(1) mu{sub B} per Cr-ion with an easy axis close to the [1 1 1-bar] direction. A magnetic moment of 4.37(3) mu{sub B} per Cr-ion was calculated from the Curie constant for the paramagnetic region. The crystal structures of the hitherto unknown Li{sub 1.8}Cr{sub 1.2}(MoO{sub 4}){sub 3} and LiCr(MoO{sub 4}){sub 2} are compared and reveal a high degree of similarity: In both structures MoO{sub 4}-tetrahedra are isolated from each other and connected with CrO{sub 6} and LiO{sub 5} via corners. In both modifications there are Cr{sub 2}O{sub 10} fragments of edge-sharing CrO{sub 6}-octahedra. - Graphical abstract: Magnetic structure of LiCr(MoO{sub 4}){sub 2}. The orientation of the magnetic moments of Cr{sup 3+} are shown by arrows.

• OSTI ID: 21372419
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 12; Other Information: DOI: 10.1016/j.jssc.2009.09.012; PII: S0022-4596(09)00447-2; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
CHROMIUM COMPOUNDS
CHROMIUM IONS
CRYSTAL STRUCTURE
INDIUM IONS
LITHIUM COMPOUNDS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MOLYBDATES
MONOCRYSTALS
NEUTRON DIFFRACTION
PARAMAGNETISM
PHASE STUDIES
ALKALI METAL COMPOUNDS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
IONS
MAGNETISM
MOLYBDENUM COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS