Influence of heat treatment on changes on structure and magnetic properties of CoSiB alloy

Purpose: This paper describes influence of heat treatment on changes on structure and magnetic properties of the amorphous Co77Si11.5B11.5 alloy. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge). Findings: The crystallization process involved by heat treatment leads to significant changes of structure and magnetic properties of amorphous Co77Si11.5B11.5 alloy. Research limitations/implications: Practical implications: The attractive properties of Co-Si-B alloy are of special interest for basic research on the materials as well as for their potential applications, like magnetic sensors. According to the results presented in this paper the examined Co77Si11.5B11.5 alloy as a soft magnetic material may be used in noise filters, saturable reactors, miniature inductance elements for abating spike noise, zero-phase current transformers, and magnetic heads etc., i.e. devices which are expected to exhibit high levels of permeability at high frequencies. Originality/value: It has been shown that thermal annealing at temperature close to the crystallization temperature leads to a significant increase of the initial magnetic permeability

Structure and magnetic properties of the amorphous Co80Si9B11 alloy

Purpose: The main aim of the paper was to study the influence of heat treatment on changes of structure and magnetic properties of the amorphous Co80Si9B11 alloy.Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe), static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge).Findings: The crystallization process involved by heat treatment leads to significant changes of phase composition and magnetic properties of amorphous Co80Si9B11 alloy. The activation energy of this process was determined by Kissinger method, which yields Ec=3.0±0.2 eV.Practical implications: According to the results presented in the present paper the examined Co80Si9B11 alloy as a soft ferromagnetic material with high permeability may be utilized in construction of more inductive components and is of great technological interest

Crystallization kinetics of an amorphous Co77Si11.5B11.5 alloy

Purpose: This paper describes crystallization kinetics and changes magnetic properties involved by process of crystallization Co-Si-B amorphous alloy. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe) static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge). Findings: In this work has been performed influence of thermal annealing on crystallization kinetics and magnetic properties amorphous Co77Si11.5B11.5 alloy. Practical implications: The attractive properties of Co-Si-B alloy are of special interest for basic research on the materials as well as for their potential applications, like magnetic sensors. The Co soft magnetic material is used in noise filters, saturable reactors, miniature inductance elements for abating spike noise, mains transformers, choke coils, zero-phase current transformers, and magnetic heads etc., i.e., devices which are expected to exhibit high levels of permeability at high frequencies. Originality/value: It has been shown that thermal annealing at temperature close to the crystallization temperature leads to a significant increase of the initial magnetic permeability

Investigations of crystallization behaviour of Co80Si9B11 amorphous alloy

Purpose: This paper describes crystallization kinetics and changes of magnetic properties involved by process of crystallization of the amorphous Co80Si9B11 alloy. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe), static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge). Findings: In this work has been performed influence of thermal annealing on crystallization kinetics and magnetic properties amorphous Co80Si9B11 alloy. Practical implications: The attractive properties of Co-Si-B alloy are of special interest for basic research on the materials as well as for their potential applications, like magnetic sensors. The Co soft magnetic material is used in noise filters, saturable reactors, miniature inductance elements for abating spike noise, mains transformers, choke coils, zero-phase current transformers, and magnetic heads etc., i.e., devices which are expected to exhibit high levels of permeability at high frequencies. Originality/value: It has been shown that thermal annealing at temperature close to the crystallization temperature leads to a significant increase of the initial magnetic permeability. The maximum permeability for examined alloy in as quenched state is about 11300

Crystallization of amorphous Co77Si11.5B11.5 alloy

Purpose: The investigation results of crystallization of amorphous Co77Si11.5B11.5 alloy in tape form, obtained by melt spinning method during annealing in temperature range 373-873 K with step of 50 K in time 1 h, have been presented in the paper. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe) static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge). Findings: The changes of magnetic properties connected with the structure changes involved by crystallization process have been investigated of amorphous Co77Si11.5B11.5 alloy. Practical implications: Amorphous magnetic materials have been around for some time and their applications can be found in many types of industrial products. They include transformers, motors, and a wide variety of magnetic components in sensors, power electronics, electrical energy control/management systems, telecommunication equipment and pulse power devices. Originality/value: It has been stated that heat treatment leads to crystallization leads to a significant increase of the initial magnetic permeability

Incommensurate magnetic order in the alpha-Fe(Te,Se) superconductor systems

Magnetic spin fluctuations is one candidate to produce the bosonic modes that mediate the superconductivity in the ferrous superconductors. Up until now, all of the LaOFeAs and BaFe2As2 structure types have simple commensurate magnetic ground states, as result of nesting Fermi surfaces. This type of spin-density-wave (SDW) magnetic order is known to be vulnerable to shifts in the Fermi surface when electronic densities are altered at the superconducting compositions. Superconductivity has more recently been discovered in alpha-Fe(Te,Se), whose electronically active antifluorite planes are isostructural to the FeAs layers found in the previous ferrous superconductors and share with them the same quasi-two-dimensional electronic structure. Here we report neutron scattering studies that reveal a unique complex incommensurate antiferromagnetic order in the parent compound alpha-FeTe. When the long-range magnetic order is suppressed by the isovalent substitution of Te with Se, short-range correlations survive in the superconducting phase.Comment: 27 pages, 7 figures, 1 tabl

Tunable (δπ, δπ)-Type Antiferromagnetic Order in α-Fe(Te,Se) Superconductors

The new α-Fe(Te,Se) superconductors share the common iron building block and ferminology with the LaFeAsO and BaFe2As2 families of superconductors. In contrast with the predicted commensurate spin-density-wave order at the nesting wave vector (π, 0), a completely different magnetic order with a composition tunable propagation vector (δπ, δπ) was determined for the parent compound Fe1+yTe in this powder and single-crystal neutron diffraction study. The new antiferromagnetic order survives as a short-range one even in the highest TC sample. An alternative to the prevailing nesting Fermi surface mechanism is required to understand the latest family of ferrous superconductors

High temperature superconductivity (Tc onset at 34K) in the high pressure orthorhombic phase of FeSe

We have studied the structural and superconducting properties of tetragonal FeSe under pressures up to 26GPa using synchrotron radiation and diamond anvil cells. The bulk modulus of the tetragonal phase is 28.5(3)GPa, much smaller than the rest of Fe based superconductors. At 12GPa we observe a phase transition from the tetragonal to an orthorhombic symmetry. The high pressure orthorhombic phase has a higher Tc reaching 34K at 22GPa.Comment: 15 pages, 4 figure