LABORATORY OF LASER TECHNOLOGIES
PROJECT BG05M2OP001-1.001-0008 | NATIONAL CENTER OF MECHATRONICS AND CLEAN TECHNOLOGIES
Manager:
Prof. Dr. Miroslav Abrashev (Sofia University St. Kliment Ohridski)
e-mail: mvabr@phys.uni-sofia.bg
phone 02 8161816
The studies are performed using Raman spectroscopy, which is a non-destructive and non-contact method. Thus, the structural and physical properties of solid, liquid and gaseous samples are examined, without the need for prior preparation of the samples. Raman spectroscopy is widely used in various fields such as physics, chemistry, geology, mineralogy, biology, pharmacy, criminology, and modern materials science – in the study of carbon nanotubes, graphene, diamond-like coatings, polymers, semiconductors, high-temperature superconductors and others.
ACTIVITIES
In addition to the traditional laboratory measurements of polarized Raman spectra at room temperature (and higher up to 600 oC), measurements of Raman spectra at low temperatures (up to 77 K) and at room temperature but at high pressures are performed. 20 GPa). These measurements are of interest to scientists studying phase transitions of substances.
SERVICES
- Measurement of Raman spectra at pressures up to 30 GPa
- Determining at what pressures structural phase transitions take place
- Resonant Raman spectroscopy
- Measurement of Raman spectra of samples at different temperatures in the range 77 K - 773 K
- Determination of phase transformations of the substance, as well as change of its electrical or magnetic properties
EQUIPMENT
- Argon laser Stellar-Pro Select 150 (Modu-Laser), generating wavelengths 515 nm, 488 nm and 458 nm;
- Optical high pressure cell Diacell uScope DAC-RT (G) (Almax easy Lab) (with diamond windows, max. Pressure - 30 GPa, max. Sample size - 0.5 mm);
- Motorized X-Y table SCANplus 75x50 - 2mm (Marzhauser Wetzlar) for Olympus BX41 microscope with automatic autofocus (allowing Raman mapping mode on the Raman spectrometer);
- Optical microcryostat MicrostatN (Oxford Instruments) (cooling with liquid nitrogen, evacuation of the working volume with a turbomolecular pump, operating temperature range 77 K - 500 K).
