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1

EPR Spectroscopy of the Mn^{2+} and Cu^{2+} Centres in Lithium and Potassium-Lithium Tetraborate Glasses

100%

Padlyak B., Wojtowicz W., Adamiv V., Burak Y., Teslyuk I.

Acta Physica Polonica A

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2010

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vol. 117

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issue 1

122-125

EN

The electron paramagnetic resonance spectra of the glasses with Li_{2}B_{4}O_{7} and KLiB_{4}O_{7} compositions doped with Mn and Cu were investigated. On the basis of obtained EPR spectra analysis it was shown that the Mn and Cu impurities are incorporated into the glass network as Mn^{2+} (^{6}S_{5/2}, 3d^{5}) and Cu^{2+} (^{2}D_{5/2}, 3d^{9}) ions. The Mn^{2+} EPR spectra in the glasses with Li_{2}B_{4}O_{7} and KLiB_{4}O_{7} compositions are characterised by the following parameters, measured at T = 300 K: isotropic g-factor (g_{iso} = 2.00 ± 0.05), isotropic hyperfine constant (A_{iso} = (8.65 ± 0.05) mT) and peak-to-peak linewidth of hyperfine components ΔB_{pp} = (3.50 ± 0.05) mT. The Cu^{2+} EPR spectra in the glasses with Li_{2}B_{4}O_{7} and KLiB_{4}O_{7} compositions, registered at T = 300 K are characterised by the same g-values (g_∥ = 2.34 ± 0.05, g_⊥ = 2.06 ± 0.05) and peak-to-peak line width of hyperfine components (ΔB_{pp}^{∥} = (5.11 ± 0.05) mT, ΔB_{pp}^{⊥} = (1.80 ± 0.05) mT), whereas anisotropic hyperfine constants show some differences (A_{∥} = (14.28 ± 0.05) mT, A_{⊥} = (2.34 ± 0.05) mT for glass with Li_{2}B_{4}O_{7} composition and A_{∥} = (14.21 ± 0.05) mT, A_{⊥} = (2.55 ± 0.05) mT for glass with KLiB_{4}O_{7} composition). The possible local structure of the Mn^{2+} and Cu^{2+} centres in the lithium and potassium-lithium tetraborate glass network has been considered.

2

Mechanical Properties of Soda-Lime-Silica Glasses with Variable Peanut Shell Contents

80%

Aktas B., Albaskara M., Yalcin S., Dogru K.

Acta Physica Polonica A

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2017

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vol. 131

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issue 3

511-513

EN

In this study, the mechanical properties of soda-lime-silica glasses were investigated by using micro-Vickers indentation tests, while varying the amount of peanut shell powder added to the glass. Peanut shell powder was obtained by grinding peanut shells. It was added as a dopant to glass at 0.5-5 wt.%, with the final glass samples being produced by melting. Peanut shell addition had led to a decreased density of the soda-lime-silica glasses, and X-ray diffraction data of the peanut shell-doped soda-lime-silica glasses indicated the presence of two crystalline phases, namely, anorthite (Na_{0.45}(Ca_{0.55}Al_{1.55}Si_{2.45}O₈) and magnesium aluminum silicate (MgAl₂Si₃O_{10})₆. The Young's modulus values of the soda-lime-silica glasses increased along with the amount of peanut shell powder added. Peanut shell addition to the soda-lime-silica glasses has also caused increased hardness. Fracture toughness values of these glass samples were in the range of 0.91-1.04 MPa m^{1/2}. Thus, the mechanical properties (e.g. E and K_{C}) of soda-lime-silica glasses could be enhanced through peanut shell addition.

3

The Effect of P_2O_5 and Heat Treatment on the Crystallization of Li_2O·2SiO_2-BaO·2SiO_2 (LS_2-BS_2) Glass

80%

Ertuğ B., Demirkesen E.

Acta Physica Polonica A

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2013

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vol. 123

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issue 2

191-192

EN

In this paper, the effects of P_2O_5 and heat treatment on the crystalline phases and microstructure of lithium disilicate-barium disilicate glass were examined. A wider and broad peak in the differential thermal analysis curve indicates a presence of surface crystallization instead of volume crystallization despite the use of nucleating agent, P_2O_5. The heat treatment schedules were planned according to differential thermal analysis data. The controlled crystallization of the compositions studied was carried out using two-stage heat treatment procedure. The glass transition temperature, T_{g} of the as-cast sample were used to determine the optimum nucleation temperature. The optimum nucleation temperature was determined to be 520°C. The crystallization was carried out at 720C and 880C for 15 min. Lithium disilicate and sanbornite was the major phases and moganite or coesite were also present depending on the heat treatment duration. Due to coexistence of lithium disilicate and barium disilicate phases, the change in the melting entropy prevented the formation of spherulitic morphology and recrystallization after further heat treatments. The rise in the crystallization temperature enhanced grain coarsening and formed massive microstructures.

4

Structures of Cu-Based Glass Forming System Doped with Iron

80%

Kozieł T., Latuch J., Czeppe T., Ratuszek W., Cios G., Zielińska-Lipiec A., Bała P.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

913-915

EN

The effects of iron additions on the structure of (Cu_{0.47}Ti_{0.34}Zr_{0.11}Ni_{0.08})_{100-x}Fe_{x} (x=0, 1.5, 3, 6) glass forming system are presented. The alloys were synthesized by arc melting of high purity elements and melt spun to form: rapidly quenched ribbons. X-ray diffraction studies showed the amorphous structure of the base and Fe-containing alloys, confirmed by the presence of exothermic peaks on differential scanning calorimetry curves. Bulk samples in the form of rods (Φ3×55 mm) were cast using a suction casting unit attached to the arc melter. Structural investigations revealed partial crystallization of the base Cu₄₇Ti₃₄Zr₁₁Ni₈ alloy. Iron additions significantly decreased the glass forming ability of the alloy, leading to primary crystallization of dendrites.

5

Formation and Structure of Nanocrystalline Al-Mm-Ni-Cu Alloys

80%

Latuch J., Krasnowski M., Ciesielska B.

Acta Physica Polonica A

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2002

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vol. 102

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issue 2

175-179

EN

This paper reports the results of a short investigation on the effect of Cu additions upon the nanocrystallization behaviour of an Al-Mm-Ni alloy. 2 at.%Cu added to a base alloy of Al_{85}Mm_{10}Ni_5 alloy by substitution for Mm (mischmetal). The control of cooling rate did not cause the formation of nanocrystals of fcc-Al phase. The nanocrystalline structure fcc-Al + amorphous phase in quarternary alloy was obtained by isothermal annealing and continuous heating method, but the last technique is more effective. The volume fraction, lattice parameter, and size of Al-phase were calculated.

6

Atomic Motion in Amorphous Solids

80%

Schober H.

Acta Physica Polonica A

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2002

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vol. 102

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issue 1

83-93

EN

Glasses and amorphous materials show, coexisting with the sound waves, a variety of low energy excitations: tunneling, quasi-localized vibrations and relaxations. The latter two are observed well into the liquid state. Using molecular dynamics both were shown to be centred on more than ten atoms or molecular units, which form chain-like structures. With increasing frequency the interaction of the quasi-localized modes with the sound waves and with each other increases, they delocalize. However, even at the so-called boson peak frequency, where the sound waves become overdamped due to the interaction, the vibrations can be decomposed into local and extended modes. Closely correlated with the local vibrations are the local relaxations, which can be envisaged as collective jumps of groups of atoms. With rising temperature both the total jump length and the number of atoms participating increases. In the melt when single jumps are no longer resolved one still observes a collective motion of chains of atoms.

7

Investigations and Applications of Nanoperm-Type Soft Magnetic Materials

80%

Hasiak M., Łukiewski M., Miglierini M., Kaleta J.

Acta Physica Polonica A

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2010

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vol. 118

|

issue 5

829-831

EN

The microstructure and magnetic properties of Fe_{82}Zr_4Nb_3B_{10}Cu_1, Fe_{80}Zr_4Mn_3B_{12}Cu_1 and Fe_{80}Zr_4Ti_3Cu_1B_{12} alloys were investigated. Using RALE software the basic parameters of transformers made from nanocrystalline alloys with about 25% and 50% of crystalline phase were calculated. The transformer made from Fe_{80}Zr_4Ti_3Cu_1B_{12} alloys after annealing at 773 K for 1-shows the lowest core losses and highest efficiency.

8

Coating Effect on Magnetic Properties of Fe_{36}Co_{36}B_{19.2}Si_{4.8}Mo_3W_1 Amorphous Ribbons

80%

Perincek F., Haciismailoglu M., Sarlar K., Haciismailoglu M., Alper M., Kucuk I.

Acta Physica Polonica A

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2014

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vol. 125

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issue 2

408-410

EN

In this research, the electrodeposition technique was employed to prepare fine-grained nickel, iron and iron-cobalt coatings with 1 μm thicknesses on the substrate of the Fe_{36}Co_{36}B_{19.2}Si_{4.8}Mo_3W_1 amorphous ribbons. The coating effect on magnetic properties was examined at room temperature using an ADE Magnetics EV9 vibrating sample magnetometer with maximum magnetic field strength of 1750 kA/m. It is found that Ni, Fe, and Fe-Co coated amorphous ribbons show 0.60, 0.71, and 1.01 T saturation magnetization, respectively, while uncoated ribbon has 1.55 T.

9

Physico-Chemical and Biological Properties of Arsenic Sulfide (As_{55}S_{45}) Nanosuspension Prepared by Milling

80%

Bujňáková Z., Shpotyuk O., Sedlák J., Pastorek M., Turianicová E., Baláž P., Ingram A.

Acta Physica Polonica A

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2014

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vol. 126

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issue 4

902-906

EN

Nanosuspension based on melt-quenched arsenic sulfide of nominal As_{55}S_{45} composition was prepared by nanomilling and tested as potential anticancer drug. Polyvinylpyrrolidone was used as steric stabilizer and inhibitor of agglomeration. Individual nanoparticles had average size of 192 nm (determined by photon cross-correlation spectroscopy) and had several times better dissolution ability in comparison with bulk As_{55}S_{45}. Effect of nanomilling is shown to be associated with formation of arsenic sulfide crystalline nanoparticles and free-volume entities located at the interface between nanoparticles and surrounding matrix as it follows from positron annihilation measurements. Cytotoxicity tests were performed using human melanoma cell line Bowes and confirmed high toxicity of the studied nanosuspension.

10

Microstructure of Zirconia-Based Sol-Gel Glasses Studied by SANS

80%

Ryukhtin V., Strunz P., Kopitsa G., Ezdakova K., Gubanova N., Ivanov V., Baranchikov A., Angelov B., Feoktistov A., Pipich V., Levinský P.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

582-584

EN

Zirconia-based bulk glasses were prepared for the first time by sol-gel method. Such materials are very promising for application as photochromic devices, catalytic systems, chemical sensors, lasers and other nonlinear optics devices. Obtained transparent and semi-transparent materials were studied by small and ultra-small angle neutron scattering (SANS and USANS) methods. As evidenced by SANS, morphology of zirconia glasses is very sensitive to parameters of sol-gel synthesis, e.g. temperature and concentration of reactants. SANS data correlates rather well with surface porosity data. Increasing water concentration in reaction mixtures containing zirconium propylate leads to a significant increase in fractal cluster size, while decrease of the temperature results in an increase of the fractal dimension. The obtained results indicate that parameters of the microstructure and consequently physical properties of zirconia glasses can be effectively controlled by parameters of synthesis.

11

Effect of Argon Plasma on the Float Glass Surface

80%

Tuleta M.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

91-93

EN

Both surfaces of a commercial float glass were treated simultaneously by a low-temperature argon plasma generated by an inductively coupled rf power supply. The effect of plasma processing on the outer surface composition of both sides of the glass was analysed by means of the ion scattering spectroscopy technique. The observed recomposition of the outer surface atoms was interpreted as a result of the action of the thermal and electric fields created by the plasma on particular glass constituents.

12

The Influence of Technological Parameters of the Casting Process on the Structure and Selected Properties of Iron-Based Metallic Glasses

70%

Pilarczyk W., Jung T., Babilas R.

Acta Physica Polonica A

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2016

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vol. 130

|

issue 4

923-926

EN

The main aim of this paper was to produce amorphous ribbons with specified composition with the use of various process parameters and X-ray qualitative and quantitative phase analysis after casting and heat treating. Station for ultra-fast cooling of the molten alloy with high vacuum pumps designed for the production of metallic glasses in the form: of ribbons with the use of Bühler Melt Spinner SC was used. The X-ray qualitative and quantitative phase analysis, microscopic observation, microhardness and thermal properties tests of the investigated ribbons were conducted. Based on experimental data the discussion on the correlation between casting process parameters, phase and quantitative composition and heat treatment was carried out.

13

Comparison of Mechanical Properties of Unidirectional and Woven Carbon, Glass and Aramid Fiber Reinforced Epoxy Composites

70%

Ekşı S., Genel K.

Acta Physica Polonica A

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2017

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vol. 132

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issue 3

879-882

EN

In this study, mechanical behavior of epoxy composite reinforced by unidirectional and woven fiber is investigated experimentally. In the preparation of composite samples woven shaped glass, aramid and carbon fibers and unidirectional shaped glass and carbon fibers were used. Tension, compression and shear tests were carried out to determine mechanical properties of composites. It is seen from the test results, that unidirectional carbon fiber shows better performance than the glass fiber. Mechanical properties of 0°-oriented unidirectional fiber are better than those of 90°-oriented unidirectional fiber. Mechanical properties of aramid-fiber-reinforced composite are higher than those of glass and carbon fiber, when the woven types of fibers are considered.

14

Magnetic Properties of Synthetic Gehlenite Glass Microspheres

70%

Majerová M., Dvurečenskij A., Cigáň A., Škrátek M., Prnová A., Kraxner J., Galusek D., Maňka J.

Acta Physica Polonica A

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2017

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vol. 131

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issue 4

699-701

EN

In the paper, gehlenite amorphous microspheres were prepared by the flame synthesis of a powder precursor. In the first step, the precursor was prepared from a stoichiometric mixture of CaCO₃, Al₂O₃ and SiO₂ by a standard solid-state reaction method. Next, the precursor was sprayed into a CH₄-O₂ flame with the temperature of around 2200°C and molten droplets of synthetic gehlenite were rapidly cooled by distilled water. Structural and detailed magnetic properties were studied by the optical microscopy, X-ray diffraction and QD SQUID magnetometer. The gehlenite microspheres show a complex magnetic behaviour that is a function of the temperature and the magnetic field, e.g. diamagnetism and paramagnetism at 300 K and 2 K, respectively.

15

The Microstructure and Thermal Stability of the Two-Component Melt-Spun Ni₅₅Fe₂₀Cu₅P₁₀B₁₀ TCMS Amorphous/Amorphous Composite

61%

Ziewiec K., Wojciechowska M., Prusik K., Mucha D., Jankowska-Sumara I.

Acta Physica Polonica A

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2016

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vol. 130

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issue 4

927-930

EN

The aim of this study is to present the special features and properties of the two alloys of similar average chemical composition Ni₅₅Fe₂₀Cu₅P₁₀B₁₀, processed through two different routes. The first alloy was melt-spun after the ejection of homogeneous liquid using a traditional single chamber crucible, and the second alloy was ejected from a double chamber crucible as two separate liquids: i.e., Ni₄₀Fe₄₀B₂₀ and Ni₇₀Cu₁₀P₂₀, mixing only at the orifice area. The studies of the microstructure of the composite alloy were performed through the use of transmission electron microscopy and scanning electron microscopy. The Ni₅₅Fe₂₀Cu₅P₁₀B₁₀ two-chamber melt-spun (TCMS) alloy, as well as the homogeneous Ni₅₅Fe₂₀Cu₅P₁₀B₁₀, Ni₄₀Fe₄₀B₂₀, and Ni₇₀Cu₁₀P₂₀ alloys, were heated to elevated temperatures and their characteristics studied by means of differential scanning calorimetry. The temperature resistivity change method was applied to the examination of the Ni₅₅Fe₂₀Cu₅P₁₀B₁₀ TCMS alloy. The phase composition after heat treatment was investigated using X-ray diffraction. The results of the microstructure examination show that the TCMS alloy is an amorphous/amorphous composite, and is notable for its Ni-Fe-B and Ni-Cu-P stripes resulting from its differentiated chemical composition. Another unique feature of the TCMS alloy is that it retains its wood-like morphology even after high-temperature heat treatment. The crystallisation of the TCMS alloy starts from the Ni-Cu-P constituent and ends with the Ni-Fe-B areas of the sample. The results are discussed on the basis of previous work completed on amorphous matrix composites.

16

Magnetic Properties and Structure of Amorphous Fe_{74}Hf_{4}Ta_{1}Cu_{1}Gd_{1}La_{x}Si_{15-x}B_{4} (x = 0, 7) Ribbons

61%

Bardziński P., Kopcewicz M., Rybaczuk M., Hasiak M., Musiał A., Kinzhybalo V., Idzikowski B.

Acta Physica Polonica A

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2015

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vol. 127

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issue 3

827-830

EN

The multi component Fe_{74}Hf_{4}Ta_{1}Cu_{1}Gd_{1}La_{x}Si_{15-x}B_{4} (x = 0, 7) alloys are promising candidates in the search for materials with unusual mechanical and magnetic properties. Amorphous nature of melt-spun samples was confirmed by X-ray diffractometry and Mössbauer spectroscopy. The X-ray diffraction patterns revealed a distinct amorphous halo. The low-field components of magnetic hyperfine field distributions on iron nuclei are observed in the Mössbauer spectra, with average hyperfine field values of 19.9 and 15.7 T for x = 0 and x = 7, respectively. Coercivity studied by vibrating sample magnetometer was about 12 A/m for x = 0 and 82 A/m for x = 7 at 300 K and about 600 A/m for x = 0 and 1200 A/m for x = 7 at 400 K. Remanence also changed with temperature, amounting to 0.64 T for x = 0 and 0.36 T for x = 7 at 300 K, while at 400 K it was 0.43 and 0.11 T for x = 0 and x = 7, respectively. It is shown that La addition has beneficial effect of shifting the Curie point towards lower temperatures together with the increase of magnitude of magnetization.

17

Glass-forming ability and thermal stability of Fe62Nb8−xZrxB30 and Fe72Zr8B20 amorphous alloys?

51%

Shapaan M., Lábár J., Varga L., Lendvai J.

Open Physics

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2004

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vol. 2

|

issue 1

104-119

EN

Glass-forming ability (GFA) and thermal stability of Fe62Nb8B30, Fe62Nb6Zr2B30 and Fe72Zr8B20 at % amorphous alloys were investigated by calorimetric (DSC and DTA) measurements. The crystallization kinetics was studied by DSC in the mode of continuous versus linear heating and it was found that both the glass transition temperature, Tg, and the crystallization peak temperature, Tp, display strong dependence on the heating rate. The partial replacement of Nb by Zr leads to lower Tg and Tx temperatures and causes a decrease of the supercooled liquid region. JMA analysis of isothermal transformation data measured between Tg and Tx suggests that the crystallization of the Fe62Nb8B30 and Fe62Nb6Zr2B30 amorphous alloys take place by three-dimensional growth with constant nucleation rate. Nb enhances the precipitation of the metastable Fe23B6 phase and stabilizes it up to the third crystallization stage. Zr addition increases the lattice constant of Fe23B6 and, at the same time, decreases the grain size.

18

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

51%

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

Acta Physica Polonica A

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2002

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vol. 102

|

issue 2

323-328

EN

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.

Refine search results

EPR Spectroscopy of the Mn^{2+} and Cu^{2+} Centres in Lithium and Potassium-Lithium Tetraborate Glasses

Mechanical Properties of Soda-Lime-Silica Glasses with Variable Peanut Shell Contents

The Effect of P_2O_5 and Heat Treatment on the Crystallization of Li_2O·2SiO_2-BaO·2SiO_2 (LS_2-BS_2) Glass

Structures of Cu-Based Glass Forming System Doped with Iron

Formation and Structure of Nanocrystalline Al-Mm-Ni-Cu Alloys

Atomic Motion in Amorphous Solids

Investigations and Applications of Nanoperm-Type Soft Magnetic Materials

Coating Effect on Magnetic Properties of Fe_{36}Co_{36}B_{19.2}Si_{4.8}Mo_3W_1 Amorphous Ribbons

Physico-Chemical and Biological Properties of Arsenic Sulfide (As_{55}S_{45}) Nanosuspension Prepared by Milling

Microstructure of Zirconia-Based Sol-Gel Glasses Studied by SANS

Effect of Argon Plasma on the Float Glass Surface

The Influence of Technological Parameters of the Casting Process on the Structure and Selected Properties of Iron-Based Metallic Glasses

Comparison of Mechanical Properties of Unidirectional and Woven Carbon, Glass and Aramid Fiber Reinforced Epoxy Composites

Magnetic Properties of Synthetic Gehlenite Glass Microspheres

The Microstructure and Thermal Stability of the Two-Component Melt-Spun Ni₅₅Fe₂₀Cu₅P₁₀B₁₀ TCMS Amorphous/Amorphous Composite

Magnetic Properties and Structure of Amorphous Fe_{74}Hf_{4}Ta_{1}Cu_{1}Gd_{1}La_{x}Si_{15-x}B_{4} (x = 0, 7) Ribbons

Glass-forming ability and thermal stability of Fe62Nb8−xZrxB30 and Fe72Zr8B20 amorphous alloys?

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