THE EXPERIMENTAL INVESTIGATION OF SUPERCONDUCTORS, USING THE YKR METHOD

Determined have been the parts of the electron structure of the intermetal compounds, type A-15; the existence of non-distortion structure of the copper-oxygen planes in ceramet 1-2-3 to be processed, has been established. The results can be used for creating the methods of integral technological control of superconductors on the microlevel, and can indicate the ways of improvement of the critical parameters of the superconducting compounds. The field of application: the physics of magnetic phenomena, material-keeping, study courses for the students and aspirantsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

The distribution of the electron density and spin density in the interplanar areas CuFeS

Chalcopyrite CuFeS2 is a known semiconductor mineral with a wide range of unique physical and chemical properties. These materials can be used as elements of solar batteries, coherent and incoherent sources of polarized radiation, in photovoltaic, thermoelectric and spintronic devices. Despite the relatively large number of studies on CuFeS2, many questions about its magnetic and electronic properties, are still outstanding. In this paper we were carried out studies of the distribution of the electron density and spin density in the nuclei of iron and copper in the semiconductor mineral CuFeS2. Special attention was devoted to interrelation of electronic and spin subsystems of the compound. The results of studies of the compound obtained in NMR 63,65Cu local field at low temperatures were used to perform the corresponding analysis. The cluster approach was used. The biggest cluster had Cu9Fe10S28-4 formula. Calculations were carried out in the framework of restricted self-consistent Hartree - Fock with open shells (SCF-LCAO-ROHF), MINI basis. The calculations were made with the “foundation” on the quadrupole parameters (quadrupole νQ frequency and the asymmetry parameter of the electric field gradient tensor η), obtained from the experiment. Study of electron density maps were performed for the regions containing chains of Fe-S-Cu and S-Fe-S for the different layers of metals and sulfur atoms. It is shown that the nature of the connection of iron atoms belonging to neighboring layers with sulfur atoms of the intermediate layer is different, which is reflected on the electron density distribution