The influence of domain structure on the variation of coercive field and maximum magnetization of Fe_77.5B_22.5 amorphous alloy

The magnetic hysteresis of Fe_77.5B_22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (H_c), maximum magnetization (M_m) and remanent magnetization (M_r) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (M_s) and that the interaction between two domain structures plays an important role in enhanced increase of H_c on M_m > 0.5 M_s. The frequency dependence of parameters of the hysteresis curve is briefly discussed

Musical Composition and Elementary Excitations of Environment

During the performance of a musical composition a special human environment comes into being. We aim to interpret the compositions as a specific class of human environment in order to utilise that for description of structure and dynamics of general human environment. In particular, we analysed four Bach\u27s fugas considering their motifs and introducing the concept of the energy of a motif. We used bosonic excitations from theoretical physics as an analogical starting point for this concept, with the aim of proposing a new way to shed light onto more complex human environments. The aim is neither to reduce music to physical theories nor to define new theories of music, but to approach the investigation of complex environments in a new way, using already existing concepts

Utjecaj domenske strukture na ovisnost koercitivnog polja i maksimalne magnetizacije amorfne slitine Fe77.5B22.5

The magnetic hysteresis of Fe77.5B22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (Hc), maximum magnetization (Mm) and remanent magnetization (Mr) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (Ms) and that the interaction between two domain structures plays an important role in enhanced increase of Hc on Mm > 0.5 Ms. The frequency dependence of parameters of the hysteresis curve is briefly discussed.Indukcijskom metodom mjerene su krivulje magnetizacije amorfne vrpce Fe77.5B22.5. Ovisnosti koercitivnog polja (Hc ), maksimalne magnetizacije (Mm ) i remanentne magnetizacije (Mr) mogu se objasniti dvostrukom domenskom strukturom karakterističnom za ovakve uzorke. Analiza mjerenja pokazuje da su unutrašnje domene odgovorne za magnetizaciju do 65% magnetizacije zasićenja (Ms) te da interakcija između dviju domenskih struktura igra važnu ulogu pri ubrzanom rastu Hc pri Mm > 0.5 Ms. Razmatrana je i ovisnost parametara krivulje histereze o frekvenciji

Utjecaj domenske strukture na ovisnost koercitivnog polja i maksimalne magnetizacije amorfne slitine Fe77.5B22.5

The magnetic hysteresis of Fe77.5B22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (Hc), maximum magnetization (Mm) and remanent magnetization (Mr) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (Ms) and that the interaction between two domain structures plays an important role in enhanced increase of Hc on Mm > 0.5 Ms. The frequency dependence of parameters of the hysteresis curve is briefly discussed.Indukcijskom metodom mjerene su krivulje magnetizacije amorfne vrpce Fe77.5B22.5. Ovisnosti koercitivnog polja (Hc ), maksimalne magnetizacije (Mm ) i remanentne magnetizacije (Mr) mogu se objasniti dvostrukom domenskom strukturom karakterističnom za ovakve uzorke. Analiza mjerenja pokazuje da su unutrašnje domene odgovorne za magnetizaciju do 65% magnetizacije zasićenja (Ms) te da interakcija između dviju domenskih struktura igra važnu ulogu pri ubrzanom rastu Hc pri Mm > 0.5 Ms. Razmatrana je i ovisnost parametara krivulje histereze o frekvenciji

Slow magnetic dynamics in the K3M3IIM2IIIF15 multiferroic system

K3Fe5F15 is a multiferroic material belonging to the K3M3IIM2IIIF15 family. Zero-field cooled and field cooled magnetization measured as a function of temperature demonstrate magnetic transition in K3Fe5F15, K3Fe3Cr2F15, and K3Cu3Fe2F15. Complementary to this, the magnetic behavior below the magnetic transition was studied via magnetic relaxation at different temperatures after switching magnetic field from H to −H. A slow change of magnetization on the hours time scale was observed and it was best described by a logarithmic time dependence for all three compounds over a broad temperature and field range. It follows that a distribution of magnetic moments over anisotropy barriers, which block the magnetic moments against reorientation, is present. We introduced a model of thermal activation of the magnetic moments of regions distributed over the barriers to describe the temperature and field dependence of the relaxation parameters. The dimensions of these magnetic regions were estimated to be of nanometer size

Electronic structure and properties of (TiZrNbCu)_1-xNi_x high entropy amorphous alloys

A comprehensive study of selected properties of four (TiZrNbCu)_1-xNi_x (x \le 0.25) amorphous high entropy alloys (a-HEA) has been performed. The samples were ribbons about 20 \mum thick and their fully amorphous state was verified by X-ray diffraction and thermal analysis. The surface morphology, precise composition and the distribution of components were studied with a Scanning electron microscope (SEM) with an energy dispersive spectroscopy (EDS) attachment. The properties selected were the melting temperature (T_m), the low temperature specific heat (LTSH), the magnetic susceptibility \chi_exp and the Young^,s modulus (E). Whereas LTSH and \chi_exp were measured for the as-cast samples, E was measured both for as-cast samples and relaxed samples (after a short anneal close to the glass transition temperature). The LTSH showed that the electronic density of states at the Fermi level, N_0(E_F), decreases with increasing x, whereas the Debye temperature (\theta_D) increases with x. This is similar to what is observed in binary and ternary amorphous alloys of early transition metals (TE) with late transition metals (TL) and indicates that N_0(E_F) is dominated by the d-electrons of the TE. The LTSH also showed the absence of superconductivity down to 1.8K and indicated the emergence of the Boson peak above 4K in all alloys.The free-electron like paramagnetic contribution to \chi_exp also decreases with x, whereas E, like \theta_D, increases with x, indicating enhanced interatomic bonding on addition of Ni. The applicability of the rule of mixtures to these and other similar HEAs is briefly discussed

Eosinophilic Granuloma of the Temporal Bone in an Adult: Controversies in the Management

Eosinophilic granuloma is a rare, benign, lesion characterized by uncontrolled proliferation of Langerhan’s cells. It is commonly found in a bone and has been described in almost every bone in the body. It usually affects children and is seldom found in adults. A case of 60-year-old adult male with an eosinophilic granuloma of the right temporal bone with infiltration of the temporal and infratemporal fossa and osteolysis of the squama of the temporal bone is presented. Diagnostic procedure and course of treatment are described. Controversies in the management and different approaches in therapy of such lesion are discussed because there is no agreed treatment protocol established