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Open access

D. Bochenek and P. Niemiec

Abstract

A lead free ceramic composite 0.9BaFe0:5Nb0:5O3-0.1Ni0:5Zn0:5Fe2O4 (BFN-NZF) with ferroelectromagnetic properties have been obtained in presented work. Ceramic composite powder obtained from the simple oxides Fe2O3, Nb2O5, ZnO, NiO and barium carbonate BaCO3. The composition of the composite was chosen so that the ratio of the BFN and NZF components was 90:10. The synthesis of components of BFN-NZF composite was performed using the calcination method. Final densification of synthesized powder has been done using free sintering. The XRD, the microstructure, EDS and dielectric investigations were performed. For comparison of the BFN ceramic and the BFN-NZF composites, temperature and frequency impedance research was conducted. Relaxation phenomena were observed at temperatures above 235°C in the BFN ceramic and above 150°C in the BFN-NZF composite. Obtained results show the coexistence of ferroelectric and magnetic properties. Such properties of obtained composites give the possibility to use them in magnetoelectric transducers.

Open access

D. Bochenek, G. Dercz and D. Oleszak

Application of Mechanical Activation in Synthesizing Multiferroic Pb(Fe1/2Nb1/2)O3 Powders

In the study, the method of high-energy powder milling - mechanical activation (MA) was used for synthesizing Pb(Fe1/2Nb1/2)O3 (PFN) powders. For the purpose of comparing the influence of high-energy milling on PFN synthesis, two groups of powder samples were used. The first mixture consisting of simple oxide powders; the second one consisting of compound oxide powders. The obtained powders were subjected to structural analysis with the use of XRD and Mőssbauer spectroscopy. Tests revealed that during the process of high-energy milling of initial constituents a partial synthesis of PFN material phases occurs. By comparing the two methods of PFN synthesizing it may be stated that mechanical activation in the case of a simple oxide mixture (PFN1) is equally effective as for a compound oxide mixture (PFN2).

Open access

R. Skulski, D. Bochenek and P. Wawrzała

Technology, Physical Properties and Phase Transitions in PMN-PT-PS Ceramics

Solid solution of (1-y)[(1-x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3]-yPbSnO3 (PMN-PT-PS) investigated in this paper is based on (1-x)PMN-xPT (PMN-PT) where, with increasing x, the transition from relaxor to ferroelectric properties is observed depending on composition. PMN-PT ceramics with 0.25< x <0.4 has been obtained using sol-gel method and next mixed together with PS ceramics obtained from oxides. Final sintering of ceramic samples was pressureless. We present the results of microstructure and XRD investigations, dielectric permittivity and hysteresis loops measurements vs. temperature.

Open access

D. Bochenek, F. Grabowski and P. Niemiec

Influence of Cobalt Admixture on the Microstructure and Dielectric Properties of PFN Ceramics

Within our work a ceramic of the PFN type was obtained by a single stage method and it was subjected to a cobalt modification in the amount of: 1.0, 2.0, 3.0, 4.0 and 6.0 mol%. Studies of the influence of the cobalt admixture on the crystalline structure, microstructure and ferroelectric properties of PFN ceramics were performed. It was shown that the iso-valence PFN admixing with cobalt had a positive influence on the density and ceramic microstructure. Higher cobalt admixtures (above 1.0 mol%) in PFN eliminate pyrochlore phase formation, and at the same time they reduce maximum electric permittivity values. The ferroelectric to paraelectric phase transition in the modified PFN compositions undergoes diffusion.

Open access

J.A. Bartkowska, R. Zachariasz, D. Bochenek and J. Ilczuk

Abstract

In the present work, the magnetoelectric coupling coefficient, from the temperature dependences of the dielectric permittivity for the multiferroic composite was determined. The research material was ferroelectric-ferromagnetic composite on the based PZT and ferrite. We investigated the temperature dependences of the dielectric permittivity (") for the different frequency of measurement’s field. From the dielectric measurements we determined the temperature of phase transition from ferroelectric to paraelectric phase. For the theoretical description of the temperature dependence of the dielectric constant, the Hamiltonian of Alcantara, Gehring and Janssen was used. To investigate the dielectric properties of the multiferroic composite this Hamiltonian was expressed under the mean-field approximation. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified.

Open access

D. Bochenek, P. Niemiec, R. Zachariasz, A. Chrobak and G. Ziółkowski

Abstract

A ferroelectric-ferromagnetic composites based on PZT powder have been obtained in presented work. The main aim of combination of ferroelectric and magnetic powders was to obtain material showing both electric and magnetic properties. Ferroelectric ceramic powder (in amount of 90%) was based on the doped PZT type solid solution while magnetic component of the composite was nickel-zinc ferrite Ni1-x ZnxFe2O4 (in amount of 10%). The synthesis of components of ferroelectric-ferromagnetic composite was performed using the solid phase sintering. Final densification of synthesized powder has been done using free sintering. For obtained of ferroelectric-ferromagnetic composites the XRD, the microstructure, EDS, dielectric, magnetic, internal friction and electrical hysteresis loop investigations were performed. Obtained results shown the correlations between the magnetic subsystem and the electrical subsystem of the ferroelectric-ferromagnetic composites. Such properties of obtained composites give the possibility to use them in memory applications of new type.

Open access

P. Niemiec, R. Skulski, D. Bochenek and P. Wawrzała

Abstract

In this work it is designed and obtained the multicomponent material with the formula 0.6075PMN-0.2025PT-0.09PS- 0.1PFN:Li (PMN-PT-PS-PFN:Li) for applications in multilayer ceramic capacitors MLCC. Obtaining of PMN-PT-PS-PFN:Li was done by two alternative methods of synthesis. In the first method a PMN-PT-PS-PFN:Li has been obtained from simple compounds (oxides, carbonates), in the second method the complex compounds (MgNb2O6 and FeNbO4) and simple compounds (oxides PbO, TiO2 and carbonate Li2CO3) were used. From synthesized powder of PMN-PT-PS-PFN:Li the ceramic samples were obtained which have next undergone comprehensive investigations. The X-ray investigations, as well as ferroelectric, dielectric and elastic investigations have been made.

Open access

P. Niemiec, R. Skulski, D. Bochenek and P. Wawrzała

Abstract

We present the results of obtaining and investigating ceramic samples of solid solution (1-x)(PbZr0.53Ti0.47O3)- x(PbFe0.5Ta0.5O3) [i.e. (1-x)PZT-xPFT] with x =0.25, 0.35 and 0.45 obtained using conventional ceramic technology. These materials belong to class of materials known as multiferroics. Solid solutions PZT-PFT are the lowest-loss room-temperature multiferroics known, and as a result there are very interesting for magnetoelectric devices. Paper presents the results of termogravimetric investigations, EDS, XRD and main dielectric measurements. It has been stated that with increasing content of PFT decreases the mean diameter of grains and more wide distribution of grain diameters is observed. For x =0.25 sharp phase transition from ferroelectric phase to paraelectric one is observed and high values of dielectric permittivity. Composition PZT-PFT with x =0.45 has the lowest values of dielectric permittivity, and the transition is more diffused. The increase of x leads also to the shift of the temperature of maximum of dielectric permittivity towards lower temperatures. Samples with x =0.25 and x =0.35 exhibit very low values of dielectric losses up to about 100°C. Dielectric losses for samples with x =0.45 are higher. For obtained PZT-PFT samples we have investigated P-E hysteresis loops at room temperature for frequency 1 Hz. For composition x =0.25 it after application the field about 2.5 kV/mm polarization is equal approximately 28 μC/cm2, while for x =0.35, and x =0.45 after application the field about 2.0 kV/mm the polarizations are equal about 25 μC/cm2 and 20 μC/cm2 respectively. Very low values of losses and high values of polarization lead to the conclusion that interesting material PZT-PFT for applications should be composition with x =0.25.

Open access

R. Zachariasz, J.A. Bartkowska, D. Bochenek and P. Niemiec

Abstract

In the work, temperature Q-1(T) and amplitude Q-1(") dependences of internal friction for ferroelectric - ferromagnetic composites on the base of the PZT and ferrite were determined. The temperature dependences of internal friction Q-1 reveal the peak in the range of high temperatures. We have investigated the peak associated with the viscous-elastic mobility of ferroelectric domain walls. The internal friction due to the viscous-elastic mobility of ferroelectric domain walls was calculated and compared with the experimental data in the reference to the Wang’s theory. Based on internal friction measurements and theoretical considerations, the peak was described. Additionally the amplitude (isothermal) Q-1(") dependences for the composites were made. This allowed for the interpretation of the maximum observed on the temperature dependences of the internal friction Q-1(T).

Open access

R. Zachariasz, D. Bochenek, K. Dziadosz, J. Dudek and J. Ilczuk

Influence of the Nb and Ba Dopands on the Properties of the PZT Type Ceramics

Investigations of an influence of an admixture of ions Ba2+ and Nb5+ on dielectric and piezoelectric properties of the Pb(Zr0.53Ti0.47)O3 (PZT) ceramics were conducted. The PZT type ceramics was synthesized by a conventional method, and compacted by a free sintering method. The PZT type specimens were poling by a low and high temperature method. It was found that there was a positive influence of adding 10mol%Ba and ~2mol%Nb simultaneously on a set of dielectric and piezoelectric parameters, which are important for practical applications of this PZT type ceramics.