Grant of International Science Foundation (ISF)

"Electron liquid in magnetically ordered multilayers. Theoretical description and Grazing Incidence Mossbauer Spectroscopy Experiments"

Summary

Experimental equipment for analysis of ultrathin films and subsurface layers in conditions of total external reflection was developed. The spectrum shape obtained depends on parameters of hyperfine interactions as well as on susceptibilities of the sublayers forming the medium under investigation, thickness of sublayers, phase distribution of Mossbauer atoms at different depth and so on. They provide very important information about electronic structure of multilayer systems.

Mossbauer spectra of a number of synthetic low-dimensional structures such as Fe/Cu and Fe/Cr superlattices with antiferromagnetic exchange coupling, mechanically alloyed Fe_1-xCu_x    (x= 0.01, 0.05, 0.10, 0.15)}, ⁵⁷Fe films subjected to the different stages of oxidation by means of natural atmosphere annealing at different temperatures, were obtained.

In the framework of the model Hamiltonian approach theoretical scheme for description of electronic and magnetic structure of low dimensional systems constructed on the base of transition d-metals was developed. Numerical calculations of the magnetic properties of films, rough surfaces and interfaces in the case when the space homogeneity is broken in the plane were carried out. Influence of magnetic structure perturbation near the surface and interface on the Mossbauer spectra was considered.

Simple models for calculation of exchange magnetic coupling and giant magnetoresistance in the superlattices were proposed. Some peculiarities of exchange coupling dependence on the thickness of nonmagnetic as well as magnetic layers were explained.

Publications

1. V.N.Gittsovich, A.K.Kazanskij, V.G.Semenov, V.M.Uzdin. Low-dimensional magnetic systems: simple theoretical models for description of electronic and magnetic structure Fizika metallov i metallovedenie 79 (1995) 41 (in Russian); Physics of Metals and Metallography, 79 (1995) 26.
2. M.A. Andreeva, V.N. Gittsovich, V.G. Semenov, V.M. Uzdin, A.I. Philichev. Mossbauer spectroscopy of total external reflection: the background of the technique and its possibilities for layer by layer analysis. Vestnic Spb. University (1995) ser. 4 , N 1(4) , 45 (in Russian).
3. V.N.Gittsovich, V.G.Semenov, V.M.Uzdin. Bulk and surface magnetic properties of dilute FeCr alloys. J. Magn. Magn. Mat. 146 (1995) 165.
4. A.K.Kazansky, V.M.Uzdin. Modelling of the magnetic properties of the Cr-Fe interface. Phys.Rev B52 (1995) 9477-9485.
5. C. Demangeat, V.M. Uzdin. Hubbard & periodic Anderson model for description of Imperfect low-dimensional FeCr magnetic systems J. Magn. Magn. Mat. 156 (1996) 202.
6. V.M. Uzdin, N.S. Yartseva. Quantum well states in the metallic magnetic trilayers and superlattices, Proceeding of ICAME-95, Italian Physical Society, Conference Proceedings, 50 (1995) p. 639.
7. V.M. Uzdin, N.S. Yartseva. Quantum wells in trilayers: dependence of the properties on the thickness of magnetic and nonmagnetic layers J. Magn. Magn. Mat. 156 (1996) 193.
8. V.M. Uzdin, L. Adamowicz, P. Kocinski. Exchange coupling in the complex magnetic multilayers. Europhys. Lett., 34 (1996) 629.

Abstracts

1. V.N.Gittsovich, M.L.Lisus, V.G.Semenov, V.M.Uzdin. Investigation of corrosion products in ultrathin layers by means of grazing incidence Mossbauer spectroscopy (GIMS) and X-ray reflection. - Abstracts of ICAME-95, Rimani (Italy) 10-16 September, p. 08-11.
2. K.B. Gerasimov, V.N.Gittsovich, V.G.Semenov, V.M.Uzdin. Mossbauer effect on mechanically alloyed Fe_1-xCu_x (x= 0.01, 0.05, 0.10, 0.15)}. - Abstracts of ICAME-95, Rimani (Italy) 10-16 September, p. 12-10.
3. V.N.Gittsovich, V.G.Semenov, V.M.Uzdin. Electronic and Magnetic Structure of thin films, rough interfaces and multilayers. - Abstracts of ICAME-95, Rimani (Italy) 10-16 September, p. 07-C12.
4. C. Demangeat, V.M.Uzdin. Hubbard and Periodic Anderson Model for description of imperfect Low-Dimensional FeCr Magnetic Systems Submitted to 2-nd International symposium on metallic multilayers. - Abstracts of MML-95, Cambridge (UK), 11-14 September, P2.80.
5. V.M.Uzdin, N.S.Yartseva. Quantum wells in trilayers: dependence of the properties on the thickness of magnetic and nonmagnetic layers. Abstracts of MML-95, Cambridge (UK), 11-14 September, P1.91.
6. V.P.Bougrov, V.N.Gittsovich, V.P.Kononov, S.G.Ovchinnikov, V.G.Semenov, V.M.Uzdin. CEMS investigation of hyperfine structure of ⁵⁷Fe in Fe/Cu multilayers. - Abstracts of HFI-95, Leuven, (Belgium), 28 August - 1 September , P224-TH.
7. V.N.Gittsovich, V.I.Minin, L.N.Romashov, V.G.Semenov, V.V.Ustinov, V.M.Uzdin. CEMS-Study of hyperfine fields distribution in Fe/Cr multilayers. - Abstracts of HFI-95, Leuven (Belgium), 28 August - 1 September, P230-TH.
8. L.Bottyan, L.Deak, E. Gerdau, V.N. Gittsovich, J. Korecki, O.Leupold, D.L.Nagy, V.G. Semenov, V.M. Uzdin. Hyperfine fields profile in oxidized Fe Films determined by means of GIMS methods. - Abstracts of HFI-95, Leuven (Belgium), 28 August - 1 September, P89MO 21.