Naslov
Crystal structure and magnetic properties of Co7(TeO3)4Br6 - a new cobalt tellurite bromide

Autori
Becker, Richard ; Johnsson, Mats ; Berger, Helmuth ; Prester, Mladen ; Živković, Ivica ; Drobac, Djuro ; Miljak, Marko ; Herak, Mirta

Izvornik
Solid State Sciences (1293-2558) 8 (2006); 836-842

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Cobalt; Oxohalide; Stereochemically active lone pair; Magnetic ordering; Antiferromagnetic; Ferromagnetic

Sažetak
The crystal structure of the new compound Co7(TeO3)4Br6 is described together with the magnetic properties. The new compound crystallizes in the monoclinic space group C2/c with the unit cell parameters a = 20.6532(5) &Aring ; ; ; , b = 8.6533(2) &Aring ; ; ; , c = 14.7262(5) &Aring ; ; ; , β = 124.897(3)◦ , Z = 4. The crystal structure was solved from single crystal data, R = 0.0242. The structure can be considered as layered and the building units are [CoO4Br2] and [CoO2Br4] octahedra and [TeO3E] tetrahedra, E being the 5s2 lone pair on the Te(IV) ions. The magnetic properties of the compound are characterised by antiferromagnetic correlations at high temperatures, strong deviation from the Curie– Weiss behaviour in a broad intermediate temperature range and long range magnetic ordering setting-in at low temperatures. Magnetic ordering takes place in stages, being represented by two susceptibility anomalies, at TN = 33 K and TC = 27 K. Themagnetic transition at TC is ferromagnetic (or ferrimagnetic) in character.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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