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The wettability of graphite by the silver–tin (Ag–Sn) liquid alloy was measured using the sessile drop method at a temperature interval of 1273–1473 K. The system is found poorly wetting with the contact angle at an interval of 125…142°. The contact angle passed through an elongated maximum as function of composition and increased with temperature. It was shown that no dissolution or chemical reaction takes place in the system up to 1473 K. The Butler equation was extended to calculate the concentration dependence of surface tension, solid/liquid interfacial energy and that of the contact angle theoretically. The theoretical results reasonably reproduce the measured values.

Two reversible relaxation processes of similar activation energies can be separated in Cr-doped FeNiSiB metallic glasses by combined Curie-point and enthalpy-relaxation measurements. While one of the processes has a positive contribution to the activation-energy spectrum of the Curie-point, the other gives a negative contribution to it. The positive effect is associated with the ordering of Fe and Ni atoms in the FeNiSiB matrix while the negative effect is attributed to the Cr atoms.

The frequency dependence of permeability change due to 1% mechanical deformation is investigated in FINEMET-type soft magnetic cores after various degree of amorphous-nanocrystalline transformation. It was found that stress sensitivity is especially high at the early stage of nanograin formation, and gradually decreases as the Si-content of the nanograin assembly increases. The permeability changes are correlated with TEM and X-ray diffraction results.

The aim of this work was to find a relation between thermal and thermomagnetic effects associated with structural phase transitions of amorphous Fe-based alloys. We have investigated Fe85−xCrxB15 amorphous alloys (0⩽x⩽11.5) by means of differential scanning calorimetry and thermomagnetometry. The measurements were carried out in the range from room temperature up to the Curie point of iron. The phases formed upon heating at high temperatures were identified by X-ray diffraction. A diagram containing the phase transformations obtained from the experimental data is presented and discussed.

The thermal, thermomagnetic properties as well as the frequency dependence of permeability are compared for bulk amorphous alloys with the composition of Fe 70.7 C 6.7 P 10.4 B 5 Si 1.1 Mn 0.1 Cr 2 Mo 2 Ga 2 and Fe 65.5 Cr 4 Mo 4 Ga 4 P 12 C 5 B 5.5 . The details of devitrification differ mainly in the thermomagnetic measurements. The shape of thermomagnetic curve hints to the formation of hard phase in the case of sample with higher Fe-content. Frequency dependence of the permeability shows unfavorable manner when the temperature of heat treatment approaches the glass transition regime. Contrary, heat treatment at 400 ∘ C has a beneficial effect on the high-frequency permeability.

H-induced increase in the amorphous Curie temperature ( T C am ) of FeCrB glassy alloys was detected where the relaxation effect associated with the measuring process is negligible. The increase is reversible and tends to disappear as the spontaneous desorption process proceeds at room temperature. The negligible effect arising from irreversible relaxation was separated successfully by applying appropriate control measurements on as quenched samples.

We have investigated the influence of chromium on the magnetic after-effect (MAE) of amorphous Fe 85 − x Cr x B 15 ( x = 0, 2, 3, 5 and 7) alloys. Isochronal curves were obtained for times t = 5, 10, 30, 60, 120 and 180 s in the temperature interval from 77 K up to T c . A computer analysis was performed to evaluate the spectra of activation energies from these measurements. The spectra of activation energies have a characteristic shape with a peak at the value of 1.2–1.4 eV. The pre-exponential factors are found to lie between 4 × 10 −13 and 1.1 × 10 −17 s. This indicates that the MAE can be assigned to short range atomic reorientation near free volumes. It follows from the isochronal MAE measurements that the addition of Cr atoms also causes a decrease in MAE amplitude as well as a decrease in Curie temperature. The higher the Cr-contents, the lower the MAE and the preexponential factor τ 0 .

The frequency dependence of permeability and power loss are investigated in FINEMET samples after isothermal heat treatments, leading to structural relaxation and/or nanocrystallization. The rapid decrease in power loss and increase in permeability at low frequencies are connected mainly with the structural relaxation and the first period of nanocrystallization. The time scale for the evolution of soft magnetic properties at high frequencies is similar to that for the density change.

A correlation was found between the change of the saturation magnetization ( M s ) and spin wave stiffness constant ( D sp ) as a function of annealing temperature for FINEMET-type glassy precursors (Fe 73.5 Nb 3 Si 13.5 B 9 Cu 1 ), annealed in the temperature range 400–540°C for times up to 1 h. During irreversible structural relaxation both M s and D sp increase. During the evolution of the nanocrystals M s decreases while D sp increases.

The influence of uniaxial compressive stresses on the energy of magnetoelastic anisotropy of an amorphous ferromagnetic alloy with composition Fe 79.1 Cr 4.3 B 16.6 has been investigated. Uniaxial pressure within a part of the sample cross-section was obtained by straightening out the ribbon annealed in a toroidal shape. The bulk value of the energy of magnetoelastic anisotropy was determined from the hysteresis loop traced with a fluxmeter. The energy of magnetoelastic anisotropy of surface layers ∼50 nm thick was determined from hysteresis loops traced with a hysteresigraph based on the transversal Kerr effect. The experimentally obtained values were found to be in good agreement with the calculated ones.

Magnetization studies were performed on amorphous Ni100−xPx alloys with 15 ≤ x ≤ 23 in the temperature range from 4.2 to 300 K and in fields up to 9 kOe. Samples with x

The sequences of crystallization and the magnetic parameters of TM 100− x − y M x B y (TM: Fe, Co; M: Au, Pt, Cr, V, Ti, W; B: boron) were investigated. Changes due to the replacement of TM by the various metallic elements are discussed on the basis of preferential distribution of M between boron-rich compound-like associations and off-stoichiometric TM clusters.

The effect of cobalt on the crystallization process and products of Ni 50− x Co x Zr 50 amorphous alloys was investigated by DSC calorimetry and transmission electron microscopy. All the samples investigated show a one-step crystallization process. The crystallized samples with 0 at.% Co, 5 at.% Co and 10 at.% Co content are characterized by an orthorhombic crystal structure. With increasing cobalt content a cubic phase was detected between the orthorhombic (Ni, Co)Zr phases.

Pulse heat treatment using 0.4 s current pulses was applied to Fe 80 B 14 Si 6 amorphous ribbons above its Curie temperature in order to avoid magnetically induced anisotropy. After relaxation the pulse heat treatment was continued while applying 128 MPa mechanical stress to obtain induced anisotropy. The results of pulse annealing were monitored by coercive force and effective anisotropy measurements carried out between the pulses at room temperature. It is shown that pulse annealing enables a magnetically soft relaxed state to be achieved and if mechanical stress is applied during the process, induced anisotropy can be developed.

A high heating rate (100 K/s) was used for measuring T c using low frequency ac permeability in that concentration range of FeB where previously only extrapolation was possible. These measurements provide a clue to the origin of the data scattering found in the literature.

It is found that the magnetic state of the amorphous Ni 60 Zr 40 samples changes from paramagnetic to superparamagnetic upon hydriding. The density and the size of the magnetic clusters induced by the hydriding process was determined by magnetic and scanning transmission electron microscopic (STEM) measurements.

FeTMB diluted alloys with different TM metallic elements and various boron concentrations were investigated to obtain information on the effect of chemical affinity to boron and of the solubility in Fe of the alloying TM element in the inhomogeneous mother alloy FeB on the mean magnetic moment and Curie temperature.

The influence of the transition metals T = Ti, V, Cr, Mn, Co, Ni, Ru, Os, Pd on the Mossbauer characteristics and corrosion resistance of Fe 80 T 3 B 17 metallic glasses was studied. It was found that the additives improving magnetic properties decrease corrosion resistance and vice versa. The changes of the isomer shift are interpreted in terms of changes of the electronic structure caused by alloying with transition metals.

All three methods of the positron annihilation technique were applied to investigate amorphous metals. Samples of Fe40Ni40Si14B6 and Fe40Ni40P14B6 were prepared by the melt spun technique with constant ejection pressure and orifice size but at varying quenching rate and melt temperature. The influence of the production process leading to different Hc for the samples, the effect of heat treatment, cold rolling, and electron irradiation were studied. The measured dependence of positron annihilation parameters on the above treatments indicates the presence of positron-active trapping centres in the amorphous phase.

The temperature- and field-dependence of magnetization, and the 31 P NMR linewidth and Knight shift of some amorphous Ni 100− x P x alloys with 18⩽ x ⩽ 22 prepared by melt-quenching and electrodeposition were studied below room temperature. Although all the alloys investigated contain magnetic inhomogeneities, the amount and nature of which depend on impurities and on the details of sample preparation, it could be established that the amorphous matrix of Ni 100− x P x alloys with x ⩾ 18 exhibit Pauli paramagnetism and the Pauli susceptibility was found to decrease rapidly with P content. From the results, a similarity of the electronic structure and the short-range order in amorphous Ni-P alloys and in the crystalline Ni 3 P compound is deduced.

Small-angle scattering of neutron (SANS) was analysed on FeB and FeNiB metallic glass ribbons by means of a double crystal small angle device and a neutron diffractometer. The dimensions of magnetic domains and small clusters were determined. An appreciable anisotropy of SANS intensity and surface scattering was observed.

The correlation between some technological parameters and magnetic properties of amorphous rapid quenched Fe 83,4 B 16,6 ribbons has been investigated. The results show an important role of the cooling rate and the melt overheating on the coercive force, magnetization and microstructure as well as on the amorphous-crystalline transformation of the alloys.

The effects of melt overheating on HV and H c of Fe-B amorphous alloys were studied. Subsequent low temperature annealing does not eliminate the difference in HV; however, definite convergence of H c was observed. The change in HV is not the same for the hypo- and hyper-eutectic concentration ranges.

Electroinsulating coatings based on boric acid and its salts as well as on orthophosphoric acid were developed and applied to Fe-B metallic glasses. Investigations were performed to study the influence of such coatings on the magnetic properties, especially the magnetization curve and magnetization losses.