Магнитные состояния ионов Fe-=SUP=-2+-=/SUP=- в Fe-=SUB=-x-=/SUB=-Mn-=SUB=-1-x-=/SUB=-S, индуцированные химическим давлением

The effect of chemical pressure (x) on the spin state of iron ions in FexMn1-xS single crystals (0.12≤ x≤0.29) is studied by the method of Mössbauer spectroscopy in the range 4.2-300 K. Features of the formation of the paramagnetic and antiferromagnetic phases for solid solutions are revealed. It was found that when x changes in FexMn1-xS, the Mn2 + cations are replaced by Fe2 + cations in the high-spin state. A decrease in the interionic distances in FexMn1-xS causes a change in the state of Fe2 + ions in the samples at x = 0.25 and 0.29. In the magnetically ordered phase at 4.2 K, the changes in the asymmetry parameter of the electric field gradient tensor (EFG) and the angle between the directions of the magnetic moment and the principal axis of the electric field gradient from 21o in the sample from x = 0.12 to 33o at x = 0.29 were observed.

Сверхтонкие взаимодействия в узлах меди диэлектрических и сверхпроводящих металлооксидов меди

The method of Mössbauer spectroscopy on isotopes 61Cu (61Ni) shows that for bivalent copper dielectric metal oxides, a combined quadrupole and Zeeman interaction of 61Ni nuclei with local fields in copper sites is observed, whereas for superconducting metal oxides, only quadrupole interaction of the nuclei 61Ni is detected. For all the metal oxides under consideration, the equal in value valence contribution to the electric field gradient tensor was found.

Mössbauer and heat capacity studies of ErZnSn2

Heat capacity results obtained for the intermetallic compound ErZnSn2 were re-analysed to also consider, apart from the classical Debye model, the anharmonicity of the crystal lattice and the proper set of Einstein modes. The 119mSn Mössbauer technique was applied to derive the hyperfine interaction parameters characteristic of the two inequivalent crystallographic Sn sites in the compound studied. Quadrupole interaction constants, as measured by 119mSn Mössbauer spectroscopy, allowed for estimations of Vzz components of the electric field gradient tensor that exist at both Sn sites in the discussed compound.

Analysis of heat capacity and Mössbauer data for LuZnSn2 compound

New analysis of heat capacity data is presented for LuZnSn2 compound that takes into account anharmonic effects together with the existence of Einstein modes. 119mSn Mössbauer spectroscopy was used to monitor the hyperfine parameters at the two crystallographically inequivalent Sn sites in the studied compound. The problem of non-unique mathematical resonance spectrum description and the problem how to choose physically meaningful set of hyperfine parameters will be thoroughly discussed. Measured quadrupole interaction constants by 119mSn Mössbauer spectroscopy give estimations for Vzz component of electric field gradient tensor at both Sn sites in LuZnSn2.