Crystal structure and magnetic properties of the new cobalt tellurite halide Co5(TeO3)4X2 (X = Cl, Br)
2007 (English)In: Solid State Sciences, ISSN 1293-2558, Vol. 9, no 3-4, 223-230 p.Article in journal (Refereed) Published
Two new cobalt tellurite halides Co5(TeO3)4Cl2 and Co5(TeO3)4Br2 have been synthesized and found to be iso-structural with Ni5(TeO3)4X2 (X = Cl, Br). Co5(TeO3)4X2 crystallizes in the monoclinic system space group C2/c, and the Br-phase has the lattice parameters a = 20.440(1) Å, b = 5.2760(2) Å, c = 16.4710(7) Å, β = 124.790(5)°, and Z = 4. The crystal structures were solved from single-crystal X-ray data, R1 = 1.90 and 1.77, respectively, for the Cl- and Br-phases. The crystal structure is layered with only weak van der Waals' interactions in between the layers. The layers are built by large [Co5O16X2] groups consisting of five edge- and face-sharing Co-octahedra. Each group is connected to adjacent groups via corner sharing through common oxygen atoms as well as through [TeO3E] groups. Magnetic susceptibility measurements on oriented single crystals reveal pronounced anisotropy in a broad temperature range and clear signs of antiferromagnetic ordering at low temperatures. Anisotropic susceptibility of an iso-structural Ni-based compound was also studied and compared with the corresponding results of Co5(TeO3)4X2. Magnetic anisotropy is discussed in framework of single-ion anisotropy effects.
Place, publisher, year, edition, pages
2007. Vol. 9, no 3-4, 223-230 p.
Oxohalide; Lone-pair elements; Crystal structure determination; Antiferromagnetism; Magnetic susceptibility
IdentifiersURN: urn:nbn:se:su:diva-23089DOI: 10.1016/j.solidstatesciences.2006.11.019ISI: 000246444300001OAI: oai:DiVA.org:su-23089DiVA: diva2:190059
Part of urn:nbn:se:su:diva-14142007-01-022007-01-022010-07-26Bibliographically approved