Vedecké zameranie

Využitie makroskopických kvantových javov, najmä makroskopickej kvantovej interferencie v supravodičoch s nízkymi a vysokými hodnotami Tc, v oblasti merania extrémne slabých magnetických polí alebo fyzikálnych veličín, ktorých zmeny môžu byť transformované na zmeny magnetického indukčného toku. Výskum je sústredený na Josephsonove spoje, RF a DC SQUIDy, supravodivé kvantové magnetometre (SKM), gradiometrické anténne systémy a ich využitie v systémoch na meranie intenzity zväzkov častíc v urýchľovačoch, meranie biomagnetických a geomagnetických polí.

VÝSLEDKY :

• Príspevok k teoretickému objasneniu interakcií v HTc supravodičoch na základe navrhnutých modelov pre 2D štruktúry a slabé spoje v granulárnych supravodičoch [7], [8], [9], [13]
• Návrh a overenie meracieho systému SQM/MHY-1 pôvodnej koncepcie na meranie a analýzu magnetizačných characteristík vysokoteplotných supravodičov s využitím supravodivého kvantového magnetometra so snímačom SQUID a a supravodivej gradiometrickej antény 2. rádu [10], [25]
• Vyšetrovanie magnetických vlastností vysokoteplotných supravodičov ([17], [20] , YBCO hysterézne krivky)
• Vyvinutá technológia prípravy RF SQUIDov, kombinované metódy kompenzácie rušivých signálov pri meraní extrémne slabých magnetických polí v magneticky netienenom prostredí [4],[5], [6], metódy určovania nízkych koncentrácií fero(feri-) magnetických látok v biologických objektoch neinvazívnym spôsobom ([14], Meranie zaprášenia pľúc ), biomonitoring životného prostredia s využitím magnetometrie
• Návrh systému na meranie intenzity a radiálnej polohy zväzku elektricky nabitých častíc v supravodivom urýchľovači ([18], [19], [21], [22], zjednodušená schéma)

ŠPECIÁLNE ZARIADENIA :

• 5-kanálový nízkoteplotný DC SQUID systém s ekvivalentnou citlivosťou ~20x10^-15 T Hz^-1/2 v pásme bieleho šumu (priemer gradiometrov: 14mm, SQUIDy sú z FSU Jena - Nemecko)
• Jednokanálový nízkoteplotný RF SQUID systém s ekvivalentnou citlivosťou ~20x10^-15 T Hz^-1/2 v pásme bieleho šumu (priemer gradiometra: 40mm, SQUID je vlastnej výroby)

VYBRANÉ PUBLIKÁCIE

1. ZRUBEC, V. - VRABCEK, P. - TEKEL, P.: Optimalization of the second order gradiometer baselength that has been designed for the measurement of weak inhomogeneous magnetic fields. Il Nuovo Cimento 2D, 1983, 2, pp.175-183.
2. VOLCKO, D.: Possible explanation of the anomalous ratio 2D_ab / k_B T_c in the range of the BCS formalism. Physica Status Solidi (b), 164, 1991, K41-K43.
3. VOLCKO, D.: Single-Particle States in a superconducting system. Physica Status Solidi (b), 167, 1991, K25.
4. SKAKALA, M. - ZRUBEC, V. - MANKA, J.: Active compensation for ambient magnetic noise in the unshielded environment. Measurement Science and Technology, 1993, 4, pp.468-472.
5. ZRUBEC, V. - MANKA, J. - SKAKALA, M.: Superconducting pick-up antenna with limited frequency bandwith. Cryogenics, 1993, 33, 10, pp.999-1004.
6. SIMACEK, I. - ZRUBEC, V. - SKAKALA, M.: RF SQUID magnetometer with simplified circuitry. Review of Scientific Instruments, 1993, 64, 8, pp.2401-2402.
7. VOLCKO, D.: A possible behaviour of weak links in granular superconductors. Physica Status Solidi (b), 178, 1993, K31-K33.
8. VOLCKO, D.: A model for deformations of two-dimensional structures. Physica Status Solidi (b), 179, 1993, K27-K29.
9. VOLCKO, D.: A possible pairing mechanism in quasi-two-dimensional structures. Physica Status Solidi (b), 175, 1993, K13-K15.
10. ZRUBEC, V. - CIGAN, A. - MANKA, J.: Simplified fast method for magnetic characteristics measurement of the HTc superconducting materials. Physica C, 223, 1994, No. 1-2, pp.90-94.
11. SIMACEK, I.- ZRUBEC, V.- MANKA, J. - URBAN, A.: Three channel magnetometer for measurement of weak magnetic fields. Elektrotechnicky casopis - Journal of Electrical Engineering 45, 1994, pp.88-90.
12. ZRUBEC, V.: Bioelectric signals in neuron structures and the Josephson effect. Medical Hypotheses, 43, 1994, pp.273-284.
13. VOLCKO, D.: Relevance of the m(T) dependence for 2D superconductivity. Physica Status Solidi (b), 181, 1994, K21-K23.
14. KRUTY, F. - SIMACEK, I. - MANKA, J. - VRABCEK, P.: Lung dust loads monitored by noninvasive magnetometric method. Central European Journal of Occupational and Environmental Medicine, 1, 1995, 1, pp.5-12.
15. VOLCKO, D.: Energy of a Josephson Junction. Physica Status Solidi (b), 188, 1995, K13.
16. ZRUBEC, V. - MANKA, J.: Optimization of noise parameters of SQUID magnetometers with external negative feedback. Cryogenics, 35, 1995, pp.451-454.
17. DANIELIK, L. - HANIC, F. - CIGAN, A. - ZRUBEC, V.- MANKA, J.: Preparation, characterization and magnetic behaviour of Pb doped superconductors. Molecular Physics Reports, 9, 1995, pp.7-13.
18. ZRUBEC, V.: Theoretical sensitivity limits of the SQUID system for measuring beam intensities of electrically charged particles in superconductive accelerators. Cryogenics, 36, 1996, pp.427-434.
19. ZRUBEC, V.: Theoretical sensitivity limits of the SQUID system for measuring the radial position of a beam of electrically charged particles in superconductive accelerators. Cryogenics, 37, 1997, pp.97-104.
20. CIGAN, A. - MANKA, J. - BUCHTA, S.: Experimental Study of the Intergranular Weak Link Structures YBa₂Cu₃O_7-x with the Help of Magnetization Measurements. Journal of Low Temp.Phys., 106, 1997, pp.447-452.
21. ZRUBEC, V. - MANKA, J.: Measurement of Beam Intensity of Electrically Charged Particles in Superconductive Accelerators using SQM. Journal of Low Temp.Phys., 106, 1997, pp.539-544.
22. MANKA, J. - ZRUBEC, V. - CIGAN, A.: Measurement of Beam Position of Electrically Charged Particles in Superconductive Accelerators using SQM. Proc. of MEASUREMENT'97 - Int. Conf. on Measurement, Smolenice, May 29-31, Eds.: I.Frollo and A.Plackova, Polygraphy of SAS Bratislava, pp.55-58.
23. SIMACEK, I. - MANKA, J. - KRUTY, F.: Sensitivity Limits of the Magnetometric Method for Measuring the Concentration of Powdered Materials. Proc. of MEASUREMENT'97 - Int. Conf. on Measurement, Smolenice, May 29-31, Eds.: I.Frollo and A.Plackova, Polygraphy of SAS Bratislava, pp.59-62.
24. ZRUBEC, V. - URBAN, A.: Superconductive quantum fluxmeter - superconductive quantum magnetometer with external feedback. Cryogenics, 37, 1997, pp.511-516.
25. ZRUBEC, V.: Theoretical sensitivity limits of the compensation method for magnetization characteristics measurement of HTc superconducting materials using LTc SQUID 2nd order gradiometer. Cryogenics, 39, 1999, pp.241-251.
26. CIGAN, A. - MANKA, J. - MAIR, M. - GRITZNER, G. - PLESCH, G. - ZRUBEC, V.: Influence of the Tl- and Hg-content on magnetic and transport properties of the Pb, Sr-doped Tl-1223 and Hg-1223 superconductors. Physica C, 320, 1999, pp.267-276.
27. PLESCH, G. - CIGAN, A. - MANKA, J. - BUCKULIAKOVA, A. - HANIC, F. - BUCHTA, S. - ANDRZEJEWSKI, B. - STANKOWSKI, J.: Magnetic properties of YBa₂Cu₃O_7-d melt textured samples prepared by powder melting process and quench and melt growth techniques. Acta Physica Polonica A, 98, 2000, pp.327-334.
28. CAMBEL, V. - KARAPETROV, G. - ELIAS, P. - HASENÖHRL, S. - KWOK, Wai-Kwong - KRAUSE, J. - MANKA, J.: Approaching the pT range with a 2DEG InGaAs/InP Hall sensor at 77 K. Microelectronic Engineering, 51-52, 2000, pp.333-342.
29. CHROMIK, S. - JERGEL, M. - HANIC, F. - JIMENEZ, S. - JERGEL, M. - STRBIK, V. - FALCONY, C. - BENACKA, S. - CHEANG-WONG, J.C. - ANDRADE, E.: Preparation and properties of precursors BA-Ca-Cu-(O,F) thin films deposited from fluorides for superconducting Tl- and Hg-based films. Thin Solid Films, 375, 2000, pp.129-133.
30. HANIC, F. - CIGAN, A. - BUCHTA, S. - MANKA, J. - VOLCKO, D. - ZRUBEC, V.: Single Domain Textured (YBa₂Cu₃O_7-d)_1-x(Ag₂O)_x Samples. Physica C, 341-348, 2000, pp.575-576.
31. BANACKY, P. - PELIKAN, P. - VALKO, M. - BUCHTA, S. - HANIC, F. - CIGAN, A.: Electron Paramagnetic Resonance of High-Tc Superconducting Composites YBa₂Cu_3-xSc_xO_6±d. J.Phys.Chem. B, 105, 2001, pp.1943-1946.
32. ZRUBEC, V.: Improved system for measurement of the magnetization characteristics of high-temperature superconductors by the compensation method in weak magnetic fields. Rev.Sci.Instrum. 72, 2001, pp.2653-2660.
33. HOSTE, S. - VAN DRIESSCHE, I. - BRUNEEL, E. - PLESCH, G. - CIGAN, A. - MANKA, J.: Influence of silver doping on the microstructure and magnetic properties of YBa₂Cu₃O₇/Ag composities. Ceramics-Silikaty, 45, 2001, pp.76-80.