Synthesis and Magnetic Properties of the KCu(IO3)3 Compound with [CuO5] Chains

authored by
Eleni Mitoudi-Vagourdi, Julia Rienmüller, Peter Lemmens, Vladimir Gnezdilov, Reinhard K. Kremer, Mats Johnsson

The new quaternary iodate KCu(IO3)3 has been prepared by hydrothermal synthesis. KCu(IO3)3 crystallizes in the monoclinic space group P21/n with unit cell parameters a = 9.8143(4) Å, b = 8.2265(4) Å, c = 10.8584(5) Å, β = 91.077(2)°, and z = 4. The crystals are light blue and translucent. There are three main building units making up the crystal structure: [KO10] irregular polyhedra, [CuO6] distorted octahedra, and [IO3] trigonal pyramids. The Jahn-Teller elongated [CuO6] octahedra connect to each other via corner sharing to form [CuO5] zigzag chains along [010]; the other building blocks separate these chains. The Raman modes can be divided into four groups; the lower two groups into mainly lattice modes involving K and Cu displacements and the upper two groups into mainly bending and stretching modes of [IO3E], where E represents a lone pair of electron. At low temperatures, the magnetic susceptibility is characterized by a broad maximum centered at ∼5.4 K, characteristic for antiferromagnetic short-range ordering. Long-range magnetic ordering at TC = 1.32 K is clearly evidenced by a sharp anomaly in the heat capacity. The magnetic susceptibility can be very well described by a spin S = 1/2 antiferromagnetic Heisenberg chain with a nearest-neighbor spin exchange of ∼8.9 K.

External Organisation(s)
Stockholm University
Technische Universität Braunschweig
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
Max Planck Institute for Solid State Research (MPI-FKF)
ACS Omega
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Peer reviewed
ASJC Scopus subject areas
Chemistry(all), Chemical Engineering(all)
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