Home > Timetable > Contribution details

Contribution Oral

X-ray spectroscopy

Microstructure of multilayer heterosystems containing Ge quantum dots with Mn in Si matrix by XAFS- spectroscopy

Speakers

  • Dr. Simon ERENBURG

Primary authors

  • Dr. Simon ERENBURG (Nikolaev Institute of Inorganic Chemistry SB RAS, Budker Institute of Nuclear Physics SB RAS)

Co-authors

Content

Electric-field manipulation of ferromagnetism has the potential for developing a new generation of electric devices to resolve the power consumption and variability issues in today’s microelectronics industry. To date, in the scientific literature are few examples of the successful synthesis of self-assembled dilute magnetic Mn quantum dots with ferromagnetic order above room temperature. For the first time, a comparative analysis of the microstructure of samples of dilute Mn solutions in quantum dots of Ge in a silicon matrix, obtained as a result of ion Mn+ irradiation was carried out within the framework of XAFS spectroscopy methods: EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near-edge structure). From the analysis of the GeK EXAFS spectra, a significant presence of Mn in the first sphere of the Ge atoms and coordination numbers and interatomic distances in Ge environment are determined. Thus, for such systems, the direct contacts of germanium and manganese atoms were first discovered and characterized. The features of the microstructure and elemental composition of multilayer Ge/Si systems containing QDs, obtained by the simultaneous molecular beam epitaxy (MBE) of Ge and Mn for various synthesis conditions, in particular, with different impurity content of Mn, are studied. From the analysis of the GeK EXAFS spectra, coordination numbers and interatomic distances were determined, intensive mixing of Ge, Si and Mn atoms was observed in all samples. The degree of diffusion of Ge/Si correlates with the temperature of growth of QD. Correlations of the coordination numbers of Si and Mn in the sphere of Ge surroundings with the amount of manganese in QDs, as well as with the temperature at which quantum dots were grown and with other synthesis conditions were established. The XAFS spectra were obtained on the BM20 channel of the ESRF in Grenoble, and on channel 8 of the Center for Nuclear Research of the Institute of Nuclear Physics of the SB RAS.

This work was carried out with the financial support of the Russian Foundation for Basic Research (No. 16-02-00175-a; No. 16-02-00397-a)