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1

Preisach Maps of Multilayered Co/Cu Structures

100%

Gutowski M., Gutowska M., Piotrowski K., Baczewski L., Wawro A.

Acta Physica Polonica A

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2000

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vol. 97

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issue 3

467-470

EN

Magnetooptical Kerr effect measurements of room temperature hysteresis loops were taken using sandwich- and multilayer-type specimens and He-Ne laser light. For maximal external field of ~250 Gs the corresponding Kerr angle reached 0.04 deg. The samples were obtained in the Institute of Physics, Polish Academy of Sciences, Warszawa, using MBE method. The structure of samples may be described by a formula: substrate-buffer layer-(xCo/yCu)_{n} -cover layer. Al_{2}O_{3} (two orientations) and MgO were used as substrates, the buffer layer was made of W, Cu or Fe, x=15, 20 or 25 Å, y=7, 8, 9, 10, 11, 12, 13, 14, and 20 Å, n=25 and 30. 50 Å of gold (Au) served as a cover layer. The genetic algorithm was subsequently used as a data processing tool, in order to reconstruct the Preisach map for each hysteresis loop. The diagrams clearly indicate changes of magnetic interactions caused by varying thicknesses of individual magnetic and non-magnetic layers.

2

Influence of Co Doping on Crystal and Magnetic Properties of Gd_2Cu_2In

86%

Gondek Ł., Szytuła A., Kaczorowski D., Szewczyk A., Gutowska M., Tyvanchuk Y., Kalychak Y.

Acta Physica Polonica A

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2012

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vol. 122

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issue 1

216-219

EN

Physical properties of Gd_2Cu_{2 - x}Co_{x}In (x = 0.1, 0.2, 0.3) samples are investigated. The paper brings results of X-ray diffraction, magnetometric as well as specific heat studies. It was found that only sample with x = 0.1 exhibits desired crystal structure. Other compositions show existence of impurities due to lack of dissolution Co atoms. For Gd_2Cu_{1.9}Co_{0.1}In sample the Curie temperature of 92.5 K was evidenced. Thus, an enhancement of ferromagnetic correlations with comparison to Gd_2Cu_2In sample was evidenced. It was found that Gd_2Cu_{1.9}Co_{0.1}In sample exhibits magnetocaloric effect within broad temperature range.

3

Investigations of Quantum Cascade Lasers for Free Space Optics Operating at the Wavelength Range of 8-12 μm

86%

Nowakowski M., Gutowska M., Szabra D., Mikołajczyk J., Wojtas J., Bielecki Z.

Acta Physica Polonica A

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2011

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vol. 120

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issue 4

705-708

EN

The paper presents analysis and preliminary investigations of quantum cascade lasers for free space optics. The lasers radiate in the long wavelength IR spectral range (8-12 μm). Because of lower effects of radiation scattering than in the case of 1.5 μm free space optics, better transmission range can be obtained. The main task of the work was experimental investigation of quantum cascade lasers taking into consideration free space optics applications. In the research, quantum cascade lasers operating in both pulse and continuous wave modes were used. The lasers spectra as well as the operation characteristics (e.g. voltage vs. current) were measured. In conclusion, the quantum cascade lasers parameters for free space optics system applications are summarized.

4

Manifestation of Spin-Glass-Like Behavior in the Organometallic Magnet

73%

Dyakonov V., Arciszewska M., Dobrowolski W., Szewczyk A., Szymczak H., Aksymentieva E., Varyukhin V., Zubov E., Gutowska M.

Acta Physica Polonica A

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2000

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vol. 97

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issue 5

863-866

EN

Ac susceptibility (χ_{ac}) and dc magnetization (M_{dc}) of the organometallic magnet Na[FeO_{6}(C_{10}H_{8}N)_{3}] have been studied in temperature range of 4.2-200 K, in an external magnetic field up to 16 kOe. Some peculiarities of the χ_{ac} and M _{dc} behavior, which are characteristic of spin-glasses, e.g. cusps in the susceptibility and zero-field-cooled magnetization, an irreversibility between the field-cooled and zero-field-cooled magnetization and dependences of the T_{cusp} temperature on the frequency and the intensity of the magnetic field, were observed at low temperatures.

5

Investigation of Free Space Optical Detection Module Operating at the Wavelength Range of 8-12 μm

73%

Gutowska M., Nowakowski M., Bielecki Z., Mikolajczyk J., Szabra D., Paliwoda R., Pedzinska M., Pawluczyk J., Gawron W.

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issue 6

1143-1147

EN

The paper presents the construction and test results of a long-term radiation detector module for free space optical communication operated at the wavelength range of 8-12 μm. In the module a Polish detector manufactured in the company Vigo System S.A. was applied. High sensitivity of the detection module was achieved through a multi-layered heterostructure HgCdTe with immersion lens, which is optimized for the radiation detection at the wavelength of 10 μm. Detector noises were reduced as a result of detector cooling by means of four-stage thermoelectric cooler. The developed detection module is dedicated to design a next-generation optical data link. The link will be characterized by a greater range in difficult weather conditions in relation to the currently offered links operating at the shorter wavelengths.

6

Transmitter with quantum cascade laser for free space optics communication system

73%

Gutowska M., Wojtas J., Pierścińska D., Nowakowski M., Pierściński K., Szabra D., Mikołajczyk J., Bielecki Z.

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2011

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issue 4

7

Crystalline Structure of Potassium Holmium Double Tungstate

52%

Borowiec M., Dyakonov V., Woźniak K., Dobrzycki Ł., Majchrowski A., Michalski E., Zubov E., Khatsko E., Zayarnyuk T., Szewczyk A., Gutowska M., Rykova A., Barański M., Domukhovski V., Shtyrkhunova V., Iwanowski P., Żmija J., Szymczak H.

Acta Physica Polonica A

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2011

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vol. 119

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issue 6

835-837

EN

The potassium holmium double tungstate was prepared by using top seeded solution growth technique. Structural investigations have been performed at room temperature. The KHo(WO_4)_2 single crystal belongs to the monoclinic space group C2/c with the unit-cell parameters: a = 10.624(2) Å, b = 10.352(2) Å, c = 7.5434(15) Å, β = 130.78(3)^{o}, and Z = 4. The atomic coordinates, isotropic and anisotropic displacement parameters and interionic distances for the studied structure were determined.

Refine search results

Preisach Maps of Multilayered Co/Cu Structures

Influence of Co Doping on Crystal and Magnetic Properties of Gd_2Cu_2In

Investigations of Quantum Cascade Lasers for Free Space Optics Operating at the Wavelength Range of 8-12 μm

Manifestation of Spin-Glass-Like Behavior in the Organometallic Magnet

Investigation of Free Space Optical Detection Module Operating at the Wavelength Range of 8-12 μm

Transmitter with quantum cascade laser for free space optics communication system

Crystalline Structure of Potassium Holmium Double Tungstate