Laboratory / Scientific group
+420 266 05 2858, +420 266 05 3533
perever [at] fzu.cz
I am an expert in experiment preparation for measurement of magnetic and electric properties of samples, experienced programmer in Labview (since 1999).
- Ph.D. work (1998-2003) was devoted to study of the magnetization process in steels using the Preisach model formalism, mostly studying differential permeability curves.
- The PostDoc project GACR 202/04/P010 “Development of a new technique for determination of magnetic properties of open-circuit ferromagnetic samples”
- (2004-2005) was devoted to the problem of reliable magnetic measurements on open circuits. As a result I developed and successfully tested the surface field extrapolation method that greatly improves accuracy of the hysteresis measurements on magnetically open samples.
- In 2006 I invented the magnetic shielding for precise and accurate surface magnetic field measurements, which in combination with the extrapolation method decreased the error in the field determination in magnetically open circuits by 10-100 times. In 2006 I tried to patent this invention with no success.
- In 2007 I started investigation of the influence of stress on the magnetization process (hysteresis loops, permeability curves) using the accurate method of the surface field measurements developed before. I found very simple formula describing changes in the magnetization – by the effective field due to stress as the product of a function of magnetization and of stress. This formula worked for all possible types of stress – applied/residual, tensile/compressive in all directions on oriented and non-oriented steels. Also it worked excellent on tempered spring steel where it was possible to determine very accurately the tempering temperature from hysteresis loop measurements.
- Starting from 2013 I work in the Department of Functional Materials in the group of Dr. Oleg Heczko focusing on magnetic properties of magnetic shape memory alloys. I perform mechanoacoustic and electromagnetic noise measurements on Heusler alloys.
- I put into operation a special setup for acoustic and electromagnetic noise measurements during the sample deformation, which was based on fast National Instruments PXI cards.
- 2013-2015 I added resistivity, AC susceptibility and dilatation measurements options to the Cryogenic magnetometer available in our group.
- In 2015 I started measurements of magnetoacoustic emission (MAE), Barkhausen noise (BN), incremental permeability (IP) and eddy currents on magnetically open steel samples. Now I am preparing also GMI measurements.
- 2009-2020 Magnetic measurements on Fe-3%Si grain-oriented steels were done together with magnetic domain observations in cooperation with Dr. Rudolf Schäfer, IFW Dresden, Germany. I made a special setup for simultaneous measurements of hysteresis loops and magnetic domains observations by Kerr microscopy.
- In 2017 I obtained first in the world magnetic domains by Kerr microscopy on Ni-Mn-Ga shape memory alloys in the martensitic state. In 2019 I managed to obtain magnetic domains also on the austenitic Ni-Mn-Ga alloy.
Hobby – electronics.