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Ing. Yvonna Jirásková, Ph.D.
Position: researcher
Groups: Multiscale Modelling and Measurements of Physical Properties (CEITEC IPM), Electrical and Magnetic Properties Group
Rooms: 305, 120
Phone numbers: +420 532 290 446, +420 532 290 312
E-mail: jirasko@DELETE-THIS.CZ@DELETE-THIS.COMipm.cz.COM
Projects
Microstructure of Fe-Al based alloys
Effects of cores and boundaries of nanograins on the structural and physical properties of ball milled and mechanically alloyed iron-based materials
Structure and magnetic properties of amorphous and nanocrystalline Fe(Ni)MoCuB based alloys
Publications:
2017

Q2 PUBLICATION:
Y. Jiraskova, J. Bursik, A. Zemanova, J. Cizek, P. Hruska, O. Zivotsky,
Effect of hydrogen on Fe and Pd alloying and physical properties,
Internationl Journal of Hydrogen Energy 42 (2017) 6885.

Description
Fe95PdH5 and Fe95Pd5 nanopowders were prepared by mechanical alloying (MA) using high energy ball milling. Two ways of the sample preparation were compared in order to examine the effect of hydrogen on MA: (i) A-sample: Pd powder was pre-charged with hydrogen and subsequent MA of Fe and PdH was performed in Ar protective atmosphere; (ii) B-sample: Fe and Pd powders were mechanically alloyed in hydrogen atmosphere. The milling procedure was interrupted and alloying followed by several experimental methods up to the final state achieved after 50 h of milling.

2016

Q1/Q2 PUBLICATION:
Lunacek J., Zivotsky O., Jiraskova Y., Bursik J., Janos P.: Thermally stimulated iron oxide transformations and magnetic behaviour of cerium dioxide/iron oxide reactive sorbents.
Mat. Charact. 120 (2016) 295-303.

Description
The paper was devoted to detailed study of the magnetically separable sorbents based on a cerium dioxide/iron oxide composite. An identification of iron oxides, their transformations Fe3O4 → gamma-Fe2O3 (epsilon-Fe2O3) → alpha-Fe2O3 and quantitative estimation of the grain size distributions in dependence on calcination temperatures have contributed to detail description of magnetic properties.


Q1/Q2 PUBLICATION:
Zivotsky O., Titov A., Jiraskova Y., Bursik J., Hendrych A., Hrabovska K., Tsepelev VS.:
Surface and bulk magnetic anisotropy in bilayered CoSiB/FeNbCuSiB and FeNbSiB/FeSiB ribbons,
J. Alloys Comp. 681 (2016) 402-411.

Description
The study was devoted to the surface and bulk magnetic anisotropy of the bilayered Co72.5Si12.5B15/Fe73.5Nb3Cu1Si13.5B9 and Fe74.5Nb3Si13.5B9/Fe77.5Si7.5B15 ribbons prepared by modernized planar flow casting technology. The thickness of ribbons was about 36 mm while the interlayer thickness reaches typically a few μm. A bending of ribbons has led to changes in both surface and bulk anisotropies which, completed with microstructure analysis, have given the basic complex data prospectively usable for sensor applications.

2015

Q1/Q2 PUBLICATION:
Cizek J., Lukac F., Prochazka I., Vlcek M., Jiraskova Y., Svec P., Janickovic D., Positive effect of hydrogen-induced vacancies on mechanical alloying of Fe and Al.
J. Alloys Comp. 629 (2015) 22-26.

Description
Nanocrystalline Fe82Al18 powders were prepared by high energy ball milling in various atmospheres. Two preparation techniques were compared: (i) mechanical milling of pre-alloyed Fe82Al18 pieces and (ii) mechanical alloying of pure Fe and Al powders. Single phase Fe82Al18 nano-powder was formed by mechanical alloying in hydrogen atmosphere while milling in nitrogen or air environment suppressed mechanical alloying due to passivation of Fe surfaces. Positron annihilation spectroscopy revealed that mechanical alloying of Fe and Al in hydrogen atmosphere is mediated by hydrogen-induced vacancies.


Jiraskova Y., Bursik J., Hapla M., Turek I.: Influence of Molybdenum on the Alloying and Physical Properties of Fe-Al,
J. Supercon. Nov. Magn. 28 (2015) 905-910.

Description
The Fe with 29 at.% Al and 1.5 at.% Mo, corresponding to THERMENOL composition, was prepared using mechanical alloying. The main attention was devoted to the dynamics of the alloying process, phase composition, and magnetic properties. The formation of a quasi-binary (Fe-Mo)-Al system was obtained after 32 h and the alloy has reached the finest structure of homogeneously distributed elements. The alloying by Mo has induced changes in magnetic properties depending on the milling time: for shorter times, the coercivity has been reduced as compared to Fe-Al alloys of similar compositions, whereas for longer times, an increase in the coercivity due to induced strains and defects has been observed.


Jandacka P., Kasparova B., Jiraskova Y., Dedkova K., Mamulova-Kutlakova K., Kukutschova, J.: Iron-based granules in body of bumblebees,
Biometals 28 (2015) 89-99.

Description
The paper deals with the presence of iron-based granules in body parts of bumblebees. Two groups of bumblebees were collected from their natural habitat, industrial landscape, and from a breeding station. Phase analysis based on X-ray diffraction has shown that iron-based granules contain magnetite and wuestite nanoparticles. Magnetoreception, i.e. the sensory function of these granules, is discussed within the paper.

2014
2013
2010
Jirásková Y., Zábranský K., Vůjtek M., Životský O.:
Changes in the hyperfine interactions in the Fe80Nb3Cu1B16 metallic glass under tensile loading
J. Magn. Magn. Mater., 322 (2010) 1939-1946
Životský O., Jirásková Y., Hrabovská K., Pištora J., de Resende VG.:
Surface Magnetic Properties and Mossbauer Spectroscopy of As-Quenched FeNiMoCuB Ribbons
IEEE Transactions on Magnetics, 46 (2010) 369-372
2009
Y. Jirásková, K. Zábranský, I. Turek, J. Buršík, D. Jančík:
Microstructure and physical properties of mechanically alloyed Fe-Mo powder
J. Alloys and Compounds 477 (2009) 55-61
2007
M. Miglierini, T. Kaňuch, M. Pavúk, Y. Jirásková, R. Zbořil, M. Mashlan, P. Švec:
Evolution of Structural Changes in Nanocrystalline Alloys with Temperature
Phys. Met. Metallography, Suppl. 104 (2007) 335-345
M. Pavúk, M. Miglierini, M. Vůjtek, M. Mashlan, R. Zbořil, Y. Jirásková:
AFM and Mössbauer spectrometry investigation of crystallization process in Fe-Mo-Cu-B rapidly quenched alloy
J. Phys.- Condens. Matter 19 (2007) 216219
Y. Jirásková, M. Maryško, R. Zbořil:
Magnetic and structural features of amorphous FeMo based alloys
J. Magn. Magn. Mater. 316 (2007) e16-e19
2004
J. Čermák, I. Stloukal and Y. Jirásková: Iron Diffusion in Alloy Fe75Mo9B15Cu1. METAL 2004 - 13th International Metallurgical & Material Conference, Hradec nad Moravicí, Czech Republic, May 18-20 2004, CD-ROM.
2003
J. Čermák, I. Stloukal and Y. Jirásková: Diffusion of Fe in Fe75Mo9B15Cu1 Amorphous Alloy During Crystallization. Nano 03 Proceedings, Brno, Czech Republic, October 21-23 2003, 236.
2002
O. Schneeweiss, Y. Jirásková, T. Žák, J. Šebek, S.F. Lin, and X.K. Yao:
Preparation and properties of FeNi-Mg/MgO nanocomposite
Czech. J. Phys. 52 (2002) 167–170
O. Schneeweiss, Y. Jirásková, J. Čermák and P. Lejček: Atomic Ordering at Grain Boundaries in Fe-Si and Fe-Al Alloys. Proceedings of International Conference on the Applications of the Mössbauer Effect (ICAME2001), Kluwer, Dordrecht, 2002, 571.
Y. Jirásková, M. Svoboda, O. Schneeweiss, and T. Žák:
Structural properties of austenitic stainless steel in the initial state and after rf plasma nitriding
Czech. J. Phys. 52 (2002) A61–A64
2001
O. Schneeweiss, Y. Jirásková, J. Čermák and P. Lejček: Comparison of Site Preferences of 57Co at Grain Boundaries in Fe-Si and Fe-Al Alloys. METAL 2001 - 10th International Metallurgical & Material Conference, Ostrava, Czech Republic, May 15-17 2001, CD-ROM.
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central european institute of technology



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Last update
19. 09. 2017