Tech Area / Field. Brief Description of TechnologyWe have proposed and developed a new method for the investigation of physical and chemical properties of ultrathin surface

• INF-ELE: Information and Communications / Microelectronics and Optoelectronics
• MAT-SYN: Materials / Materials Synthesis and Processing
• PHY-PFA: Physics / Particles, Fields and Accelerator Physics
• INS-MEA: Instrumentation / Measuring Instruments

Brief Description of Technology
We have proposed and developed a new method for the investigation of physical and chemical properties of ultrathin surface layers and interfaces [1-2]: grazing incidence Mossbauer spectroscopy (GIMS). This method combines the advantages of two physical phenomena: the Mossbauer effect and the total external reflection of resonance radiation. During the investigations the theory and methodology of GIMS were developed. New physical effects – resonant dependence of the secondary radiation yield and the formation of standing resonant waves under grazing angles – has been discovered [3].

GIMS enables quantitative investigation with very high depth resolution. Such resolution cannot be obtained with conventional schemes of Mossbauer spectroscopy and could compete with electron spectroscopy. The method also gives information required for other techniques of ultrathin surface-layer investigation. Moreover, GIMS allows simultaneous measurement of the micro- and macroscopic properties of the surface.

All of the above mentioned problems cannot be solved by conventional methods. The GIMS method is realized in the new Mossbauer spectrometer SM 1101TER of original construction.

The outstanding feature of this spectrometer is that it allows simultaneous registration of Mossbauer spectra over a wide range of grazing angles based on: specularly reflected gamma-rays, secondary electrons, characteristic X-rays and scattered gamma-rays on four independent channels.

Simultaneous registration of all these types of radiation at the grazing incidence complement one another and expand the information on the structure and features of interaction of the radiation with ultrathin surface layers. A detailed description of the SM 1101TER Mossbauer spectrometer is given in [1].

Legal Aspects
The new design schemes used in the SM 1101TER Mossbauer spectrometer are protected by patents.

Special Facilities in Use and Their Specifications
None in this research.

Scientific Papers
1. Irkaev S.M., Andreeva M.A., Semenov V.G. et al "Grazing Incidence Mossbauer Spectroscopy: A New Method for Surface Layer Investigation": part. I: Instrumentation, Nucl. Instr. & Meth., B74 (1993), 545-553; part II: Theory of GIMS, Nucl. Instr. & Meth., B74, (1993) 554-564; Part III: Interpretation of Experimental Data, Nuclear Instr. & Meth., B103 (1995) 351-358.

2. Andreeva M.A., Irkaev S.M., and Semenov V.G. "Mossbauer Total External Reflection: Composition of Surface Layers", Hyperfine Interactions, 96 (1995) 11-22.

3. Andreeva M.A., Belozerskii G.N., Grishin O.V., et al "Effect of Base Assymetry in Conversion Electron Mossbauer Spectroscopy under Total External Reflection", Sov. Phys. JETP Lett., 55 (1962) 62-55.

4. Andreeva M.A., Irkaev S.M., and Semenov V.G. "Grazing Incidence Mossbauer Spetroscopy Determination of Photo- and Conversion Electron Yield Function", JETP, 78 (1994) 956-965.

5. Andreeva M.A., Irkaev S.M., and Semenov V.G. "Secondary radiation emission at Mossbauer total external reflections", Hyperfine Interactions, 97/98 (1996) 605-623.

6. Andreeva M.A., Irkaev S.M., Semenov V.G. et al. "Grazing Incidence X-ray, Mossbauer and Time-Domain Investigation of Ultrathin Zr/Fe_xCr_1-x/Cr-Films," ICAME-97, Rio de Janeiro, 1997, accepted.

Дата добавления: 2015-07-20