Selenite and tellurite halides of 3d metals as possible low-dimensional magnets: synthesis, crystal structures and properties

Datum

27.09.2017

Zeit

10:00 - 11:00

Sprecher

Dr. Peter S. Berdonosov

Zugehörigkeit

Department of Chemistry, Lomonosov Moscow State University

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Christine Malbrich

Beschreibung

Magnetism in low-dimensional magnetic systems is a hot topic due to the wide range of physical phenomena exhibited by them. Usually the magnetic subsystem formation is related to the peculiarities of the crystal structure of the substance. Selenite and tellurite compounds are attractive to the search for low-dimensional magnets due to the strong asymmetric surrounding of selenium or tellurium atoms and presence of active pairs of electrons, which act as nonvisible ligand comparable to the oxygen atom in volume Such electron pairs tend to form cavities, channels or even layers in the crystal structures. As the result, the selenite or tellurite groups also tend to order in the crystal structure. Finally layered (2D) or low-dimensional (1D, 0D) crystal structure may form. The presence of 3d- metal ions in such structure may lead to low-dimensional magnetic subsystem formation and related magnetic properties. In our work, a number of systems with low-dimensional magnetic behavior were prepared and characterized. Copper (II) ions with S = 1/2 compounds Sr2M(SeO3)2Cl2 (M = Co, Ni, Cu), SrCu2(SeO3)2Cl2, CaCu2(SeO3)2Cl2, PbCu2(XO3)2Cl2 (X= Se, Te). The iron (III) compound S = 5/2 Bi2Fe(SeO3)2OCl3 was found to be quasi one dimensional magnetic. The search for selenium analogues of FeTe2O5X (X = Cl, Br) compounds lead to the formation of new mixed tellurium-selenium compound with composition Fe[(Te1.5Se0.5)O5]Cl with new structure. Ref: 1. P.S. Berdonosov et.al, J Solid State Chem. 182(2009)77-82 2. O. Janson et.al., Phys. Rev. B 83, (2011)144423 3. P.S. Berdonosov et.al, Dalton Trans. 42 (2013) 9547-9554 4. P.S. Berdonosov et.al, Inorg. Chem 53 (2014) 5830-5838 5. K. V. Zakharov et.al, Phys. Rev. B 90 (2014) 214417

Links

• Seminars at the IFW

Letztmalig verändert: 27.09.2017, 10:03:25