Synthesis, crystal structure, and magnetic properties of a Li8FeSm22O38 single crystal

Li8FeSm22O38 single crystals have been grown by spontaneous flux crystallization, and their structure has been identified by X-ray diffraction analysis as follows: cubic crystals, a = 11.9078(5) , sp.gr. , Z = 2. Fe atoms occupy two mixed positions. Magnetic ions have different ligand environments: a regular octahedron (Sm/Fe)O-6, a three-cap trigonal prism SmO9, and a square antiprism SmO8. The rather low Neel temperature (similar to 3 K) can be explained by the considerable variation in the angles and lengths of exchange couplings between magnetic ions.