The features of the magnetic interactions in manganese stannide Mn1.66Fe0.02Sn with a structure of the B82 type are investigated on the basis of Mössbauer-effect measurements on the iron and tin atoms. The Curie temperature of this compound according to the Fe57 data is TC=265K, while for Sn119 it is TC=250K; both of these are higher than the value of TC determined by the Faraday method (240K). The participation of the tin atoms in the magnetic exchange interaction in MnII–Sn–MnII chains is confirmed. It is shown that effectively only three of the five manganese atoms occupying the trigonal–bipyramidal MnII positions nearest to a tin atom have any influence on the magnetic interactions at the tin nucleus. The magnetic fields at the nuclei of the manganese atoms in the trigonal–bipyramidal positions in MnII–Sn–MnII chains are significantly (2–2.5 times) larger than the field at the nuclei of the manganese atoms in the octahedral positions in MnI–MnI.

3d-metal antimonides: Fe1+x Sb, N+x Sb, Co+x Sb and the (Ni1−y Fe y )Sb solid solution have been studied by the Mössbauer effect method at 57Fe and 119Sn. It was found that the quadrupole interactions at the Fe and Sn nucleus in 3d-metal antimonides are very sensitive to the filling of different crystallographic sites with metal atoms. The metal atoms in trigonal-bipyramidal sites have a strong effect on the quadrupole splitting of 119Sn. They are nearest to anions (Sb or Sn) with the typical axial ratio of c/a = 1.25. The QS(x) dependence of 119 Sn in 3d-metal antimonides in the 0 ≤ x ≤ 0.1 concentration range can be used to determine x – the concentration of transition metal excess relative to the stoichiometric composition.

3d-metal antimonides: Fe1+x Sb, N+x Sb, Co+x Sb and the (Ni1-y Fe (y) )Sb solid solution have been studied by the Mossbauer effect method at Fe-57 and Sn-119. It was found that the quadrupole interactions at the Fe and Sn nucleus in 3d-metal antimonides are very sensitive to the filling of different crystallographic sites with metal atoms. The metal atoms in trigonal-bipyramidal sites have a strong effect on the quadrupole splitting of Sn-119. They are nearest to anions (Sb or Sn) with the typical axial ratio of c/a = 1.25. The QS(x) dependence of Sn-119 in 3d-metal antimonides in the 0 <= x <= 0.1 concentration range can be used to determine x - the concentration of transition metal excess relative to the stoichiometric composition.

The surface and surface layers of CoxCu100−x inhomogeneous thin films irradiated by an oxygen ion beam for a long time (to 100 min) are studied. The films are obtained by electrolytic deposition. With X-ray photoelectron spectroscopy and conversion electron Mössbauer spectroscopy, it is shown that the irradiation leads to the formation of an oxidized surface layer. The continuity and thickness of the layer depend on the roughness of the initial film. For a cobalt content of 8≤x≤20 at. %, the oxide layer is continuous and nonuniform in thickness, the mean thickness being estimated at several tens of nanometers. The interface between the layer and the underlying film is sharp. The films irradiated are smoother than the asdeposited ones. The formation of the oxide layer is treated in terms of a qualitative model.

PbTeSnSe and GeSnTe compound semiconductors were studied by 119 Sn Mössbauer spectroscopy in the temperature range from 5 to 240 K. Analysis of temperature dependences of the quadrupole splitting of Mössbauer spectra measured during a cooling-heating cycle confirmed the presence of off-center atoms in these materials.

The features of formation of needle-shaped Fe and FeCu particles in pores of anodic aluminum oxide and the effect of composition and crystal and magnetic structure of the particles on the properties of the resulting magnetic heterostructures were studied.

A direct experimental proof of the adequateness of the unharmonically unstable oxygen atom's sublattice model for the YBa2Cu3-xFexO7-delta-base high temperature superconductor is received on the basis of the temperature dependence of the quadrupole splitting of Fe-57 Mossbauer spectra. (C) 1998 Elsevier Science B.V. All rights reserved.

Direct experimental proof of adequacy of the unharmonically unstable oxygen atom's sublattice model in the YBa2CU3-xFexO7-delta base high temperature superconductor was received on the bases of temperature dependence of Quadrupole Splitting of Mossbauer spectra.