Results found: 3

Number of results on page

Search results

Sort By:

Limit search:

Nanocrystallisation of Soft Magnetic Fe-Co-Zr-Cu-B Alloys

100%

Wlazłowska A., Ferenc J., Latuch J., Kulik T.

Acta Physica Polonica A

2002

vol. 102

issue 2

323-328

In the present study, Fe_{41}Co_{41}B_{10}Zr_7Cu_1 alloy has been investigated in order to evaluate its thermal stability and structure after heat treatment, as well as the impact of heat treatment on magnetic properties. X-ray diffractometry, differential scanning calorimetry, chemical composition microanalysis, transmission electron microscopy, and magnetic hysteresis loop measurement techniques were employed. The crystallisation temperature of the as-quenched alloy is 490ºC (continuous heating at 5ºC/min). The melt-spun ribbon having 27μm in thickness was annealed for 1 hour at temperatures from 400 to 700ºC. The alloy after treatment at about 550ºC underwent primary crystallisation, with the average size of crystals under 20 nm. This specimen shows the coercive field of 38 A/m, as compared to about 160 A/m reported for a similar alloy (Fe_{44}Co_{44}B_4Zr_7Cu_1) with a similar structure, annealed at 600ºC.

Entropy Change Calculations for Pure Gd and a Ni-Mn-Cu-Ga Heusler Alloy: Constant Field vs. Constant Temperature Experiment

76%

Ferenc J., Kowalczyk M., Wróblewski R., Cieślak G., Sielicki K., Leonowicz M., Kulik T.

Acta Physica Polonica A

2015

vol. 128

issue 1

111-115

The magnetocaloric effect may be assessed indirectly by expressing it as the change in magnetic entropy in varying magnetic field, H, as the function of temperature, T. Magnetization, M=f(T,H), may be experimentally acquired from a series of isothermal measurements with variable field, or from a series of constant field measurements with variable temperature. The accuracy of magnetic entropy calculation depends on the number of series in these experiments. The aim of this work is to determine how little data is sufficient to obtain accurate results of magnetic entropy change calculations, on the basis of real, magnetocaloric materials. Pure gadolinium and a Ni-Mn-Cu-Ga Heusler alloy were studied. For both materials, the magnetic entropy change and relative cooling power were calculated from both experiments, with the decreasing number of experimental data. For both materials, the constant field experiment with only 6 field values provided only a 5% error of calculations, as compared to the experiment with 100 field values. The Arrott plots were also drawn for constant field mode with 6 field values, easily indicating the order of transition. Comparison of the calculation results suggests that the constant field mode magnetization measurement may be more accurate and faster than isothermal mode.

Mössbauer Study of Magnetic Properties of Fe_{80-x}Co_{x}Zr_7Si_{13} (x = 0-30~at.%) Boron-Free Amorphous Alloys

76%

Kopcewicz M., Grabias A., Latuch J., Ferenc J., Żuberek R., Nesteruk K.

Acta Physica Polonica A

2012

vol. 121

issue 5-6

1257-1260

Amorphous Fe_{80-x}Co_{x}Zr_7Si_{13} (x = 0-30 at.%) alloys in which boron was completely replaced by silicon as a glass forming element have been prepared by melt quenching. Partial substitution of iron by cobalt caused the increase of the hyperfine field and saturation magnetization. The specialized rf-Mössbauer measurements revealed that all amorphous alloys studied are magnetically very soft. The rf-sidebands effect, related to magnetostriction, increases with the increase of Co content. In Fe_{50}Co_{30}Zr_7Si_{13} sample the rf field exposure induced partial crystallization of amorphous phase that was attributed to mechanical deformations related to high frequency magnetostrictive vibrations induced by the rf field. The measurements of the hysteresis loop revealed that coercivity increases for higher Co content.

Refine search results

3 Acta Physica Polonica A

1 2015

1 2012

1 2002

3 Ferenc J.

2 Kulik T.

2 Latuch J.

1 Cieślak G.

1 Grabias A.

1 Kopcewicz M.

1 Kowalczyk M.

1 Leonowicz M.

1 Nesteruk K.

1 Sielicki K.

1 Wlazłowska A.

1 Wróblewski R.

1 Żuberek R.

Search results

Nanocrystallisation of Soft Magnetic Fe-Co-Zr-Cu-B Alloys

Entropy Change Calculations for Pure Gd and a Ni-Mn-Cu-Ga Heusler Alloy: Constant Field vs. Constant Temperature Experiment

Mössbauer Study of Magnetic Properties of Fe_{80-x}Co_{x}Zr_7Si_{13} (x = 0-30~at.%) Boron-Free Amorphous Alloys