T. V. Gubaidulina

Diagnostics of a spatial spin-modulated structure using nuclear magnetic resonance and Mössbauer spectroscopy

Methods of the diagnostics of the spatial spin-modulated structure of the cycloidal type in multiferroics based on nuclear magnetic resonance and Mössbauer spectroscopy have been considered. It has been established that Mössbauer spectroscopy makes it possible to determine the anharmonicity parameter of the spatial spin-modulated structure of the cycloidal type with no worse accuracy than nuclear magnetic resonance with higher resolution. Mössbauer spectroscopy, being sensitive to the hyperfine quadrupole interaction of the nucleus in the excited state, makes it possible to obtain additional information on the features of the spatial spin-modulated structure.

Mössbauer study of layered iron hydroxysulfides: Tochilinite and valleriite

Natural and synthetic layered iron hydroxysulfides: tochilinite and valleriite, have been investigated by Mössbauer spectroscopy. Tochilinite, magnetite, troilite, and pyrite phases were found in the products of tochilinite synthesis under different conditions. The relative contents of the phases found are determined as functions of the relative magnesium content in the initial mixture. Crystallochemical identification of the 57Fe subspectra of valleriite has been performed.

Structure of the local environment and hyperfine interactions of 57Fe probe atoms in DyNiO3 nickelate

The local structure of DyNiO3 nickelate at both sides of the insulator (T < Tim) ↔ metal (T > Tim) phase transition was studied by probe 57Fe Mössbauer spectroscopy. The character of change in the hyperfine parameters of probe iron atoms specifically near the phase-transition temperature (T ≈ Tim) was analyzed.

Temperature investigations of the spatial spin-modulated structure of multiferroic BiFeO3 by means of Mössbauer spectroscopy

The results from 57Fe Mössbauer spectroscopic studies of multiferroic BiFeO3 in a range of tem-peratures including that of the magnetic phase transition are presented. The Mössbauer spectra are processed and analyzed by reconstructing the hyperfine magnetic field distributions and interpreting the spectra with a cycloid-type spatial spin-modulated structure model. The temperature dependences of the hyperfine spectrum parameters (the Mössbauer line shift, the quadrupole shift, and the isotropic and anisotropic contributions to the hyperfine magnetic field) are obtained, along with the anharmonicity parameter of an incommensurate spin wave.

Mössbauer investigations of the CaMn7O12 double manganite with the nuclei of 57Fe probe atoms

AbstractThe CaMn7O12 double perovskite-like manganite is studied using Mössbauer spectroscopy with 57Fe impurity atoms. The hyperfine parameters of the Mössbauer spectra are found to reflect the specific local structure of this oxide. It is found that the phase transition at T ≈ 90 K is associated with the ordering of the magnetic moments of manganese cations in the octahedral sublattice. The structural phase transition R % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXgatC% vAUfeBSjuyZL2yd9gzLbvyNv2CaeHbd9wDYLwzYbItLDharyavP1wz% ZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqiVy0df9qqqrpepC0xbb% L8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpe% pae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaam% aaeaqbaaGcbaWaa0aaaeaaiqaacaWFZaaaaaaa!3AFE!

57Fe and 119Sn probe Mössbauer spectroscopy investigation of perovskite-type double manganite family CaCuxMn7−xO12 (x = 0, 0.15, 3)

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ELECTRONIC STATE OF THE 57FE PROBE ATOMS IN PEROVSKITES LAMO3 (M = NI, CU)

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