Hyperfine magnetic field at Si nuclei in Fe-Si alloys

Abstract

Calculations of the hyperfine magnetic field at silicon nuclei are conducted for Fe 1−x Si x alloys and the results are compared with experimental data available. The effect of the atomic environment on the formation of the hyperfine fields at iron and silicon nuclei is discussed. Some contradictions in early experimental studies are explained.Keywords Fe and its alloys · LAPW calculation · Nuclear magnetic resonance · Mossbauer spectroscopy Fe-Si alloys and their combinations with other elements are widely used in engineering. Their magnetic properties and peculiarities of chemical ordering are an object of research of many scientific groups. In spite of a long history of study of these alloys (for example, [1-4]) some questions related with the local properties remain unclear. Suitable experimental methods to study local properties are nuclearresonance methods which combine a wide applicability with a simple usage and high precision of measuring the hyperfine interaction (HFI). Nuclear-resonance experiments complement magnetic and structural measurements, as the parameters of HFI are directly connected with the electron and spin densities at resonance nucleus (which can be related to the partial charge and the local magnetic moment of the atom, correspondingly), and the relative intensity of subspectra can be attributed to the number of atoms being in different structural environments. But even using contemporary mathematical methods for the spectra decomposition, such as [5][6][7], one cannot reliably interpret the experimental spectra of systems with large number of nonequivalent atoms without theoretical first-principles calculations. The calculations of electron structure in frames of the density functional theory appear as an additional research method which, by its reliability, approaches importance

Magnetic domain and local atomic structures of the Fe0.94Si0.06 alloy before and after thermomagnetic treatment in an alternating-current magnetic field

“…Despite a nearly century long history of the inves tigation and practical application of soft magnetic iron-silicon alloys with a silicon concentration of 5-10 at %, which are the base materials for electrical steels, the atomic structure and its relation to magnetic properties of these alloys have so far attracted much attention of specialists [1][2][3][4]. Of particular impor tance is the investigation of the mechanisms of action on the domain structure and magnetic properties of soft magnetic iron-silicon alloys subjected to heat treatment in a magnetic field or in a field of mechani cal stresses that have been used to control the magnetic permeability and to obtain the specified magnetic properties [5,6].…”