The paper presents the technology of ferroelectric-ferromagnetic ceramic composites obtained from PLZT powder (the chemical formula Pb 0.98 La 0.02 (Zr 0.90 Ti 0.10) 0.995 O 3) and ferrite powder (Ni 0.64 Zn 0.36 Fe 2 O 4), as well as the results of X-ray powder-diffraction data (XRD) measurement, microstructure, dielectric, ferroelectric, and magnetic properties of the composite samples. The ferroelectric-ferromagnetic composite (P-F) was obtained by mixing and the synthesis of 90% of PLZT and 10% of ferrite powders. The XRD test of the P-F composite shows a two-phase structure derived from the PLZT component (strong peaks) and the ferrite component (weak peaks). The symmetry of PLZT was identified as a rhombohedral ferroelectric phase, while the ferrite was identified as a spinel structure. Scanning electron microscope (SEM) microstructure analysis of the P-F ceramic composites showed that fine grains of the PLZT component surrounded large ferrite grains. At room temperature P-F composites exhibit both ferroelectric and ferromagnetic properties. The P-F composite samples have lower values of the maximum dielectric permittivity at the Curie temperature and a higher dielectric loss compared to the PLZT ceramics, however, the exhibit overall good multiferroic properties.

The study presents a ferroelectric-ferromagnetic composite based on a doped PZT-type and ferrite powders. Ferroelectric powder (in amount of 90 wt-%) was based on multicomponent PZT-type materials, while nickel-zinc ferrite Ni 1-x Zn x Fe 2 O 4 (in amount of 10 wt-%) served as the magnetic component of the composite. The syntheses of the ferroelectric-ferromagnetic composite's components were performed using solid-phase sintering, while final densification of the synthesized powder was achieved using free sintering. X-ray analysis of the composite confirmed the presence of strong maxima originating from particular PZTtype material phases, as well as weak peaks from the Ni 0.64 Zn 0.36 Fe 2 O 4 ferrite , without foreign phases. The microstructure of the fracture of the ferroelectric-ferromagnetic composites shows that the ferrite grains on the surface of the ferroelectric component are distributed heterogeneously. Magnetic studies have characterized composite as a soft ferromagnetic material. The study indicated the influence of the magnetic subsystem on the electrical properties. In the two-phase PBZTMC-NZF ceramic composite, the magnetic component causes the decrease in electric permittivity and increased value of the dielectric losses. *przemyslaw.niemiec@us.edu.pl

Abstract. In the paper the influence of mechanical activation of the powder on the final dielectric properties lead-free Ba(Fe 1/2 Nb 1/2 )O3 (BFN) ceramic was examined. The BFN ceramics were obtained by 3-steps route. Firstly, the substrates were pre-homogenized in a planetary ball mill. Than, the powder was activated in vibratory mill (the shaker type SPEX 8000 Mixer Mill) for different duration between 25 h and 100 h. The influence of the milling time on the BFN powder was monitored by X-ray diffraction. The diffraction data confirmed that the milling process of the starting components is accompanied by partial synthesis of the BFN materials. The longer of the high-energy milling duration the powders results in increasing the amount of amorphous/nanocrystalline content. The mechanically activated materials were sintered in order to obtain the ceramic samples. During this temperature treatment the final crystallisation of the powder appeared what was confirmed by XRD studies. The performed dielectric measurements have revealed the reduction of the dielectric loss of the BFN ceramics compared to materials obtained by classic methods.

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In the work, the multicomponent Pb 0.75 Ba 0.25 (Zr 0.65 Ti 0.35 ) 1-a Sn a O 3 (PBZT/Sn) ceramics were obtained with various tin amounts (a from the range of 0.0 to 0.1). The densification of the PBZT/Sn ceramic samples was performed using pressureless sintering method. The effect of SnO 2 content on the crystal structure of PBZT/Sn ceramics, microstructure, DC electrical conductivity and electrophysical properties (including dielectric and ferroelectric testes), were investigated. The PBZT/Sn ceramic samples exhibit high values of dielectric permittivity at the temperature of ferro-paraelectric phase transition and show the relaxor character of phase transition. Excessive SnO 2 contents doping of the PBZT/Sn materials (already for a = 0.1) might lead to lattice stress and structure defects, which successively leads to the deterioration of ferroelectric and dielectric properties of the ceramic samples. The presented research shows that the addition of SnO 2 to the base PBZT compound (in the proper proportion) gives an additional possibility of influencing the parameters essential for practical applications, from the areas of micromechatronics and microelectronics.

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