ИСТИНА

Compounds with magnetic ion distributed in low-dimensional or layered structures are promising objects for low-dimensional magnets construction. One way to obtain low dimensional magnetic structure is the inclusion into the substance composition the ions with lone electron pairs such as Se4+, Te4+, Bi3+, etc. In addition the introducing halide ions as spacer into such compounds may increase the trend to form low dimensional crystal structure [1, 2]. As the result of applying of this concept we report successful synthesis of new compound Bi2Fe(SeO3)2OCl3, its crystal structure and some magnetization measurements. The titled compound was successfully synthesised by reaction of Bi2O3, SeO2 and FeCl3 in molar ratio 1 / 2 / 1 in sealed quartz tube (300°C 60-72 hrs). New compound crystallize in monoclinic P21/m space group with cell constants a = 8.5703(18) Å, b = 7.1374(15) Å, c = 8.6043(19) Å, ß = 107.090(3)°, Z = 2. The crystal structure of Bi2Fe(SeO3)2OCl3 may be considered as 2D layered structure. Zigzag FeO6 chains are run along 0 1 0 direction of the structure. These FeO6 octahedrons chains are linked by Bi(2)O3Cl3 and Bi(1)O4Cl3 polyhedrons and SeO3 groups into the layers. It may be noted that closest distance between iron atoms in the chain is 3.569(1) Å whereas the distances between nearest iron atoms from different chains are 8.570(2) and 8.604(2) Å. These chains are responsible for the magnetic behavior of the titled compound. At elevated temperatures, the magnetization of the Bi2Fe(SeO3)2OCl3 demonstrates broad maximum which indicates the formation of short – range correlation regime. At lower temperatures Bi2Fe(SeO3)2OCl3 exhibits a magnetic phase transition at T = 12.9 K This work was performed under support of RFBR grant 12-03-00665-а. [1] D. W. Bruce, D. O'Hare, R. I. Walton Functional Oxides John Wiley & Sons,2010, p. 318 Chapters 1 and 2 [2] J.-G. Mao, H.-L. Jiang, F. Kong. Inorg. Chem., 47(2008) 8498