Elemir Usak - Academia.edu (original) (raw)

Papers by Elemir Usak

Research paper thumbnail of Adaptive testing of Materials using Preisach Model Parameters Variations - Introductory Tests

Advances in Electrical and Electronic Engineering, Jun 30, 2011

A new diagnostic method (MAT - Magnetic Adaptive Testing) for non-destructive testing of ferromag... more A new diagnostic method (MAT - Magnetic Adaptive Testing) for non-destructive testing of ferromagnetic construction materials (i.e. iron based) under mechanical stress is under development, [1]. The method is based on the investigation of the correlation between the mechanical load and the parameters of Preisach-like model describing magnetic properties of such materials as the differential permeability matrix. To get the set of model parameters needed, a number of minor hysteresis loops under defined exciting magnetic field strength waveform shape H(t), especially with constant field change rate dH(t)/dt required (which implies the inducted voltage to be proportional to the differential permeability), is to be measured. The influence of initial magnetic state of the investigated material, algorithm of demagnetisation process, the slope of time dependence of exciting magnetic field on the signal-to-noise ratio and stability of the measured signal is discussed.

Research paper thumbnail of Design of magnetic cloak for experiments in AC regime

IEEE Transactions on Applied Superconductivity, 2016

Research paper thumbnail of The Dispersion Characteristics of the Complex Permeability of NiZnCu Ferrite and its Composite Materials

Advances in Electrical and Electronic Engineering, Apr 7, 2011

Research paper thumbnail of Magnetic and Structural Properties of Nickel Zinc Ferrites Doped With Yttrium

Ieee Transactions on Magnetics, 2015

ABSTRACT The aim of this paper is to investigate the effect of Y3+ ions substitution for Fe3+ ion... more ABSTRACT The aim of this paper is to investigate the effect of Y3+ ions substitution for Fe3+ ions in Ni0.42Zn0.58YxFe2-xO4(x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) compounds, synthesized by means of ceramic technique, on the magnetic properties and magneto-chemical composition and structure. It was achieved by the X-ray spectroscopy, analysis of the behavior of susceptibility with changing temperature, magnetic hysteresis loop measurement, and complex permeability spectra.

Research paper thumbnail of COMPUTER CONTROLLED SYSTEM FOR COMPLEX PERMEABILITY MEASUREMENT IN THE FREQUENCY RANGE OF 5 Hz − − − − 1 GHz

Two different methods have been used to determine the complex permeability over the frequency ran... more Two different methods have been used to determine the complex permeability over the frequency range 5 Hz to 1 GHz of sev-eral toroidal−shaped spinel ferrite samples. Automated measurements are obtained by means of two different computer controlled analyzers. At low frequencies (5 Hz − 10 MHz), an inductance measurement method is used. A simple method was used to elimi-nate the coil effects from the sample response. At high frequencies (1 MHz − 1 GHz), a coaxial transmission line measurement method has been used. The operation principle as well as calibration and compensation procedures for both the analyzers are dis-cussed. Measurements are optimised by the partial elimination of undesirable influences. For computer control and measurement process, two different programs have been written in the VEE environment (Agilent technology).

Research paper thumbnail of An optimization of experimental data processing for the MAT method application

Magnetic adaptive testing (MAT) is a new method of magnetic non-destructive inspection of structu... more Magnetic adaptive testing (MAT) is a new method of magnetic non-destructive inspection of structural mechanical properties of magnetic construction materials. Principle of MAT consists in analysis of several magnetic properties I a wide range of input variables and to find the degeneration function with optimum correlation to inspected degeneration physical process. This involves processing of large amounts of experimental data. We present a new software tool for data processing based on application of various digital filters. A novel approach of statistical analysis and thresholding using masks was introduced to data analysis and thus qualitatively improving MAT optimisation process.

Research paper thumbnail of Substituted NiZn ferrites for passive sensor applications

The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by mea... more The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology. The influence of small Be and/or Cu substitution on various magnetic properties of NiZn ferrites (such as eg the Curie temperature Tc, coercivity Hc, initial permeability µi, complex permeability μ , saturation magnetisation Ms and hysteresis loop shape) has been analysed by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and possible applications of such materials in sensor technology. A strong correlation between the substituent content and resulting properties has been observed, thus allowing preparation of material with the properties tailored for any particular application.

Research paper thumbnail of Magnetic properties of Ni ferrites substituted by divalent Zn, Cu and Co ions

Research paper thumbnail of Coupling losses and transverse resistivity of multifilament YBCO coated superconductors

Journal of Physics: Conference Series, 2006

We studied the magnetization losses of four different types of filamentary YBCO coated conductors... more We studied the magnetization losses of four different types of filamentary YBCO coated conductors. A 10 mm wide YBCO coated conductor was subdivided into 20 filaments by laser ablation. We measured the frequency dependence of the total losses in the frequency range 0.1 Hz < f < 608 Hz. The coupling loss was obtained from the total by subtracting the hysteresis loss. The latter was measured at low frequencies since only hysteresis loss is nonnegligible at frequencies below 1 Hz. The transverse resistivity, ρ tr , was determined from the coupling losses; it was assumed that the sample length is equal to half of the twist pitch. The values of ρ tr deduced from the loss data were compared with those obtained by the four-point measurements with current flowing perpendicular to the filaments. Preliminary results indicate the existence of electrical contacts between the superconducting filaments and the substrate in some areas of the samples. This was also confirmed by the Hall probe mapping of the magnetic field in the vicinity of the tape. The measured transverse resistivity was close to the resistivity of the substrate (Hastelloy).

Research paper thumbnail of Influence of Cu2+ ions on structural and magnetic properties of NiZn ferrites

Journal of Materials Science: Materials in Electronics, 2007

The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by mea... more The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology. The influence of small Cu substitution on the microstructural and magnetic properties of NiZn ferrites have been analysed by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and possible applications of such

Research paper thumbnail of Frequency dispersion of permeability in ferrite polymer composites

Journal of Magnetism and Magnetic Materials, 2003

The permeability spectra of sintered MnZn ferrite and magnetopolymers prepared by mixing the ferr... more The permeability spectra of sintered MnZn ferrite and magnetopolymers prepared by mixing the ferrite particles with polymer have been studied. The experimental data have been compared with predictions of magnetic circuit model described for dynamic conditions. The applied model analyses the effect of the demagnetising field due to shape and size of ferrite particles.

Research paper thumbnail of Magnetic properties of Be or Cu-substituted NiZn ferrites

Journal of Magnetism and Magnetic Materials, 2006

Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1-xMexFe2O4 where Me is Be or... more Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1-xMexFe2O4 where Me is Be or Cu and x=0.05, 0.1 and 0.25 have been prepared by a ceramic method. Selected magnetic properties such as Curie temperature Tc and saturation magnetization Ms of the ferrites have been measured and discussed. Complex initial (relative) permeability μ˜=μ′-jμ″ measurements have also been performed on the samples in

Research paper thumbnail of Comparision of simulated and measured magnetisation curves using a rigorously identified moving Preisach model

Journal of Magnetism and Magnetic Materials, 2000

ABSTRACT The consequent identification of the Preisach function requires a knowledge of the corre... more ABSTRACT The consequent identification of the Preisach function requires a knowledge of the correct hypothetical field, allowing the transformation of measured first-order reversal curves from external to internal field dependencies. In the present paper we discuss the difficulties we met during the application of theoretically correct algorithm to soft magnetic materials with Preisach function concentrated near macroscopic coercivity and with relatively low non-congruency.

Research paper thumbnail of The correlation between the complex permeability and the stray flux in the gaps between the laminations

Journal of Magnetism and Magnetic Materials, 1996

The dependences of the components of the complex permeability on the frequency and field strength... more The dependences of the components of the complex permeability on the frequency and field strength are significantly affected by the magnetic cooperation between oriented laminations in the yoke. The correlation between the flux distribution in the gaps and the resulting magnetic properties, such as the complex permeability, etc., has been found.

Research paper thumbnail of Microwave properties of some substituted LiZn ferrites

Journal of Magnetism and Magnetic Materials, 2008

Substituted Li ferrites with chemical composition Li0.5+0.5t−0.5xFe2.5−1.5t−0.5xTitZnxO4, where t... more Substituted Li ferrites with chemical composition Li0.5+0.5t−0.5xFe2.5−1.5t−0.5xTitZnxO4, where t=0.55 and x=0.1, 0.2, 0.3 and 0.4 with additions of 0.005 Bi2O3 and 0.05 MnO2 were synthesised by a ceramic method and selected parameters such as Curie temperature Tc, saturation induction Bs and coercivity Hc were measured and discussed. The complex permeability of prepared ferrites was measured in the frequency range of

Research paper thumbnail of Contribution to analysis of Cu-substituted NiZn ferrites

Journal of Magnetism and Magnetic Materials, 2009

ABSTRACT Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1−xMexFe2O4 where Me... more ABSTRACT Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1−xMexFe2O4 where Me is Cu with x=0.05, 0.1 and 0.25 have been prepared by a ceramic method. Certain magnetic properties such as the coercivity Hc, initial permeability μi and saturation magnetisation Ms of the ferrites have been measured and discussed from the point of view of the substituting element contents as well as the total pore volume. The Mössbauer spectra of selected samples have been analysed as well. According to the requirement of particular applications, the properties of NiZn ferrite have to be improved by means of proper substitution of selected ions.

Research paper thumbnail of Contribution to laminar effects in magnetic yokes

Journal of Magnetism and Magnetic Materials, 1996

The design of the magnetic cores of electromagnetic devices constructed from oriented materials r... more The design of the magnetic cores of electromagnetic devices constructed from oriented materials requires knowledge of the magnetic parameters of the materials in an applied external field at arbitrary directions with respect to the easy axis. Some parameter effects that can arise in stacked cores are presented and a model for the domain structure is proposed to describe the magnetic parameters.

Research paper thumbnail of Supplementary domains variation in stack of sheets

Journal of Magnetism and Magnetic Materials, 1991

ABSTRACT

Research paper thumbnail of Magnetic and structural properties of nickel zinc ferrite nanoparticles synthesized at room temperature

Journal of Applied Physics, 2004

Nickel zinc ferrite nanoparticles (Ni 0.20 Zn 0.44 Fe 2.36 O 4 ) have been produced at room tempe... more Nickel zinc ferrite nanoparticles (Ni 0.20 Zn 0.44 Fe 2.36 O 4 ) have been produced at room temperature, without calcination, using a reverse micelle process. Particle size is approximately 7 nm as determined by x-ray powder diffraction and transmission electron microscopy. Saturation magnetization values are lower than anticipated, but are explained by elemental analysis, particle size, and cation occupancy within the spinel lattice. Extended x-ray absorption fine structure analysis suggests that a significant amount of Zn 2ϩ , which normally occupies tetrahedral sites, actually resides in octahedral coordination in a zinc-enriched outer layer of the particles. This ''excess'' of diamagnetic Zn can thus contribute to the overall decrease in magnetism. Further, this model can also be used to suggest a formation mechanism in which Zn 2ϩ is incorporated at a later stage in the particle growth process.

Research paper thumbnail of Pulse nickel electrolytic colouring process of anodised aluminium

Journal of Applied Electrochemistry, 2010

The influence of frequencies of periodic reverse current on the morphology of nickel-pigmented al... more The influence of frequencies of periodic reverse current on the morphology of nickel-pigmented aluminium finishes has been studied. The pigmentation of the anodised aluminium was realised by electrolytic colouring in electrolytes with additives and in additives-free electrolytes. Additives-free electrolytes generally provide advantageous quality of pigmentation with regular and homogenous nickel morphology on the aluminium substrate at all applied frequencies. The presence of 5-sulphophtalic acid additive strongly influences the deposit quality. The deposits obtained from nickel sulphate electrolytes at all used frequencies with the use of periodic reverse current with citrate acid and sulphosuccinic acid additives provide the similar poor quality of colouring under studied plating conditions.

Research paper thumbnail of Adaptive testing of Materials using Preisach Model Parameters Variations - Introductory Tests

Advances in Electrical and Electronic Engineering, Jun 30, 2011

A new diagnostic method (MAT - Magnetic Adaptive Testing) for non-destructive testing of ferromag... more A new diagnostic method (MAT - Magnetic Adaptive Testing) for non-destructive testing of ferromagnetic construction materials (i.e. iron based) under mechanical stress is under development, [1]. The method is based on the investigation of the correlation between the mechanical load and the parameters of Preisach-like model describing magnetic properties of such materials as the differential permeability matrix. To get the set of model parameters needed, a number of minor hysteresis loops under defined exciting magnetic field strength waveform shape H(t), especially with constant field change rate dH(t)/dt required (which implies the inducted voltage to be proportional to the differential permeability), is to be measured. The influence of initial magnetic state of the investigated material, algorithm of demagnetisation process, the slope of time dependence of exciting magnetic field on the signal-to-noise ratio and stability of the measured signal is discussed.

Research paper thumbnail of Design of magnetic cloak for experiments in AC regime

IEEE Transactions on Applied Superconductivity, 2016

Research paper thumbnail of The Dispersion Characteristics of the Complex Permeability of NiZnCu Ferrite and its Composite Materials

Advances in Electrical and Electronic Engineering, Apr 7, 2011

Research paper thumbnail of Magnetic and Structural Properties of Nickel Zinc Ferrites Doped With Yttrium

Ieee Transactions on Magnetics, 2015

ABSTRACT The aim of this paper is to investigate the effect of Y3+ ions substitution for Fe3+ ion... more ABSTRACT The aim of this paper is to investigate the effect of Y3+ ions substitution for Fe3+ ions in Ni0.42Zn0.58YxFe2-xO4(x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) compounds, synthesized by means of ceramic technique, on the magnetic properties and magneto-chemical composition and structure. It was achieved by the X-ray spectroscopy, analysis of the behavior of susceptibility with changing temperature, magnetic hysteresis loop measurement, and complex permeability spectra.

Research paper thumbnail of COMPUTER CONTROLLED SYSTEM FOR COMPLEX PERMEABILITY MEASUREMENT IN THE FREQUENCY RANGE OF 5 Hz − − − − 1 GHz

Two different methods have been used to determine the complex permeability over the frequency ran... more Two different methods have been used to determine the complex permeability over the frequency range 5 Hz to 1 GHz of sev-eral toroidal−shaped spinel ferrite samples. Automated measurements are obtained by means of two different computer controlled analyzers. At low frequencies (5 Hz − 10 MHz), an inductance measurement method is used. A simple method was used to elimi-nate the coil effects from the sample response. At high frequencies (1 MHz − 1 GHz), a coaxial transmission line measurement method has been used. The operation principle as well as calibration and compensation procedures for both the analyzers are dis-cussed. Measurements are optimised by the partial elimination of undesirable influences. For computer control and measurement process, two different programs have been written in the VEE environment (Agilent technology).

Research paper thumbnail of An optimization of experimental data processing for the MAT method application

Magnetic adaptive testing (MAT) is a new method of magnetic non-destructive inspection of structu... more Magnetic adaptive testing (MAT) is a new method of magnetic non-destructive inspection of structural mechanical properties of magnetic construction materials. Principle of MAT consists in analysis of several magnetic properties I a wide range of input variables and to find the degeneration function with optimum correlation to inspected degeneration physical process. This involves processing of large amounts of experimental data. We present a new software tool for data processing based on application of various digital filters. A novel approach of statistical analysis and thresholding using masks was introduced to data analysis and thus qualitatively improving MAT optimisation process.

Research paper thumbnail of Substituted NiZn ferrites for passive sensor applications

The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by mea... more The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology. The influence of small Be and/or Cu substitution on various magnetic properties of NiZn ferrites (such as eg the Curie temperature Tc, coercivity Hc, initial permeability µi, complex permeability μ , saturation magnetisation Ms and hysteresis loop shape) has been analysed by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and possible applications of such materials in sensor technology. A strong correlation between the substituent content and resulting properties has been observed, thus allowing preparation of material with the properties tailored for any particular application.

Research paper thumbnail of Magnetic properties of Ni ferrites substituted by divalent Zn, Cu and Co ions

Research paper thumbnail of Coupling losses and transverse resistivity of multifilament YBCO coated superconductors

Journal of Physics: Conference Series, 2006

We studied the magnetization losses of four different types of filamentary YBCO coated conductors... more We studied the magnetization losses of four different types of filamentary YBCO coated conductors. A 10 mm wide YBCO coated conductor was subdivided into 20 filaments by laser ablation. We measured the frequency dependence of the total losses in the frequency range 0.1 Hz < f < 608 Hz. The coupling loss was obtained from the total by subtracting the hysteresis loss. The latter was measured at low frequencies since only hysteresis loss is nonnegligible at frequencies below 1 Hz. The transverse resistivity, ρ tr , was determined from the coupling losses; it was assumed that the sample length is equal to half of the twist pitch. The values of ρ tr deduced from the loss data were compared with those obtained by the four-point measurements with current flowing perpendicular to the filaments. Preliminary results indicate the existence of electrical contacts between the superconducting filaments and the substrate in some areas of the samples. This was also confirmed by the Hall probe mapping of the magnetic field in the vicinity of the tape. The measured transverse resistivity was close to the resistivity of the substrate (Hastelloy).

Research paper thumbnail of Influence of Cu2+ ions on structural and magnetic properties of NiZn ferrites

Journal of Materials Science: Materials in Electronics, 2007

The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by mea... more The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology. The influence of small Cu substitution on the microstructural and magnetic properties of NiZn ferrites have been analysed by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and possible applications of such

Research paper thumbnail of Frequency dispersion of permeability in ferrite polymer composites

Journal of Magnetism and Magnetic Materials, 2003

The permeability spectra of sintered MnZn ferrite and magnetopolymers prepared by mixing the ferr... more The permeability spectra of sintered MnZn ferrite and magnetopolymers prepared by mixing the ferrite particles with polymer have been studied. The experimental data have been compared with predictions of magnetic circuit model described for dynamic conditions. The applied model analyses the effect of the demagnetising field due to shape and size of ferrite particles.

Research paper thumbnail of Magnetic properties of Be or Cu-substituted NiZn ferrites

Journal of Magnetism and Magnetic Materials, 2006

Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1-xMexFe2O4 where Me is Be or... more Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1-xMexFe2O4 where Me is Be or Cu and x=0.05, 0.1 and 0.25 have been prepared by a ceramic method. Selected magnetic properties such as Curie temperature Tc and saturation magnetization Ms of the ferrites have been measured and discussed. Complex initial (relative) permeability μ˜=μ′-jμ″ measurements have also been performed on the samples in

Research paper thumbnail of Comparision of simulated and measured magnetisation curves using a rigorously identified moving Preisach model

Journal of Magnetism and Magnetic Materials, 2000

ABSTRACT The consequent identification of the Preisach function requires a knowledge of the corre... more ABSTRACT The consequent identification of the Preisach function requires a knowledge of the correct hypothetical field, allowing the transformation of measured first-order reversal curves from external to internal field dependencies. In the present paper we discuss the difficulties we met during the application of theoretically correct algorithm to soft magnetic materials with Preisach function concentrated near macroscopic coercivity and with relatively low non-congruency.

Research paper thumbnail of The correlation between the complex permeability and the stray flux in the gaps between the laminations

Journal of Magnetism and Magnetic Materials, 1996

The dependences of the components of the complex permeability on the frequency and field strength... more The dependences of the components of the complex permeability on the frequency and field strength are significantly affected by the magnetic cooperation between oriented laminations in the yoke. The correlation between the flux distribution in the gaps and the resulting magnetic properties, such as the complex permeability, etc., has been found.

Research paper thumbnail of Microwave properties of some substituted LiZn ferrites

Journal of Magnetism and Magnetic Materials, 2008

Substituted Li ferrites with chemical composition Li0.5+0.5t−0.5xFe2.5−1.5t−0.5xTitZnxO4, where t... more Substituted Li ferrites with chemical composition Li0.5+0.5t−0.5xFe2.5−1.5t−0.5xTitZnxO4, where t=0.55 and x=0.1, 0.2, 0.3 and 0.4 with additions of 0.005 Bi2O3 and 0.05 MnO2 were synthesised by a ceramic method and selected parameters such as Curie temperature Tc, saturation induction Bs and coercivity Hc were measured and discussed. The complex permeability of prepared ferrites was measured in the frequency range of

Research paper thumbnail of Contribution to analysis of Cu-substituted NiZn ferrites

Journal of Magnetism and Magnetic Materials, 2009

ABSTRACT Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1−xMexFe2O4 where Me... more ABSTRACT Polycrystalline NiZn ferrites with the chemical formula (Ni0.3Zn0.7)1−xMexFe2O4 where Me is Cu with x=0.05, 0.1 and 0.25 have been prepared by a ceramic method. Certain magnetic properties such as the coercivity Hc, initial permeability μi and saturation magnetisation Ms of the ferrites have been measured and discussed from the point of view of the substituting element contents as well as the total pore volume. The Mössbauer spectra of selected samples have been analysed as well. According to the requirement of particular applications, the properties of NiZn ferrite have to be improved by means of proper substitution of selected ions.

Research paper thumbnail of Contribution to laminar effects in magnetic yokes

Journal of Magnetism and Magnetic Materials, 1996

The design of the magnetic cores of electromagnetic devices constructed from oriented materials r... more The design of the magnetic cores of electromagnetic devices constructed from oriented materials requires knowledge of the magnetic parameters of the materials in an applied external field at arbitrary directions with respect to the easy axis. Some parameter effects that can arise in stacked cores are presented and a model for the domain structure is proposed to describe the magnetic parameters.

Research paper thumbnail of Supplementary domains variation in stack of sheets

Journal of Magnetism and Magnetic Materials, 1991

ABSTRACT

Research paper thumbnail of Magnetic and structural properties of nickel zinc ferrite nanoparticles synthesized at room temperature

Journal of Applied Physics, 2004

Nickel zinc ferrite nanoparticles (Ni 0.20 Zn 0.44 Fe 2.36 O 4 ) have been produced at room tempe... more Nickel zinc ferrite nanoparticles (Ni 0.20 Zn 0.44 Fe 2.36 O 4 ) have been produced at room temperature, without calcination, using a reverse micelle process. Particle size is approximately 7 nm as determined by x-ray powder diffraction and transmission electron microscopy. Saturation magnetization values are lower than anticipated, but are explained by elemental analysis, particle size, and cation occupancy within the spinel lattice. Extended x-ray absorption fine structure analysis suggests that a significant amount of Zn 2ϩ , which normally occupies tetrahedral sites, actually resides in octahedral coordination in a zinc-enriched outer layer of the particles. This ''excess'' of diamagnetic Zn can thus contribute to the overall decrease in magnetism. Further, this model can also be used to suggest a formation mechanism in which Zn 2ϩ is incorporated at a later stage in the particle growth process.

Research paper thumbnail of Pulse nickel electrolytic colouring process of anodised aluminium

Journal of Applied Electrochemistry, 2010

The influence of frequencies of periodic reverse current on the morphology of nickel-pigmented al... more The influence of frequencies of periodic reverse current on the morphology of nickel-pigmented aluminium finishes has been studied. The pigmentation of the anodised aluminium was realised by electrolytic colouring in electrolytes with additives and in additives-free electrolytes. Additives-free electrolytes generally provide advantageous quality of pigmentation with regular and homogenous nickel morphology on the aluminium substrate at all applied frequencies. The presence of 5-sulphophtalic acid additive strongly influences the deposit quality. The deposits obtained from nickel sulphate electrolytes at all used frequencies with the use of periodic reverse current with citrate acid and sulphosuccinic acid additives provide the similar poor quality of colouring under studied plating conditions.