In this work, the results of studies concerning the structure of polycrystalline and amorphous alloys are presented. The samples were produced in a single-step production process, using two different production methods, and under a protective argon atmosphere. The quenching speed of the molten alloy was different for each of the production methods. Samples were subjected to analysis using X-ray diffractometry, scanning electron microscopy, and computer tomography. It has been shown that the samples manufactured with a higher cooling rate feature an amorphous structure; On the other hand, the samples obtained using the method with the lower cooling speed consist of crystallites of three crystalline phases with sizes of the order of μm. The amorphous samples exhibited a varied fracture surface as well as an increase in the contribution of pores to their volume, in comparison to the samples obtained at the lower cooling speed.
The aim of this paper were studies of the structure and magnetic properties of the bulk Fe_{60}Co_{10}W_xMo_{2}Y_{8}B_{20-x} (x=0, 1, 2) alloys. Ingots of the alloys were prepared by arc melting of high purity elements in an argon atmosphere. The samples in the form of plates were obtained by a rapid solidification of liquid metal in a copper mold cooled with water. Topography of produced samples were examined using a ZEISS SUPRA 35 high resolution scanning electron microscope. Furthermore, using a vibrating sample magnetometer the magnetization in high magnetic fields was studied. Moreover, from initial magnetization curves the parameters related with the Holstein-Primakoff paraprocess were determined.
This paper presents the results of studies on the magnetic properties of the Fe_{60}Co_{10}Mo_{2}Y_{8}B_{20} alloy. The samples were fabricated in the form of plates by the injection-casting method. The structure of the investigated alloy, in the as-quenched state and after annealing, was verified by using X-ray diffractometry. The magnetization curves as a function of temperature were measured by a force magnetometer. From thermomagnetic curves the Curie temperature of the alloy was determined. As a critical parameter β was chosen to be equal to 0.36 for these calculations, it confirmed that the alloys may be considered as ferromagnetic of the Heisenberg type. Additionally, using a vibrating sample magnetometer the magnetization and coercivity field were studied (in magnetic field up to 2 T).
The study analyzed the influence of structural defects on the process of magnetization in the area called the approach to ferromagnetic saturation for bulk Fe_{60}Co_{10}W_xNb_2Y_{8}B_{20-x} (x=0, 1) alloys. For this purpose, the magnetization studies were performed in the fields range of 0 T to 2 T using a LakeShore vibrating magnetometer. On the basis of the Kronmüller theory an analysis of the magnetization curves was conducted and the type of occurring structural defects in the studied alloys was established. Then, using a Monte Carlo method the effective anisotropy of the tested samples was designated.
This paper presents studies of the bulk amorphous alloys: Fe₆₀Co₁₀Mo₂Y₈B₂₀ and Fe₆₀Co₁₀Mo₂W₁Y₈B₁₉; Both compounds were obtained by means of the injection-casting method in which liquid alloy is forced under pressure into a copper mould. The structure of the samples was studied using X-ray diffraction and scanning electron microscopy. Based on the results of the X-ray diffraction studies, it was found that the samples were in the amorphous state. Scanning electron microscopy image analysis of fractured alloy samples indicated the presence of areas of varying degrees of relaxation: "smooth", "vein", and "flake" fractures. The manufactured ferromagnetic samples were characterized by so-called soft magnetic properties with a relatively high Curie temperature of more than 520 K. In the investigated samples, the saturation magnetization was found to have been decreased from 1.14 T to 1.13 T after the addition of W. Tungsten also contributed significantly to an increase in the value of the coercive field, from 27 A/m to 8685 A/m. Following the addition of just 1% of W to the alloy, a substantial change was observed in the form: of the static magnetic hysteresis loop: characterized by the so-called "wasp" shape. This result shows that an additional magnetically hard phase had appeared within the sample.