Przemysław Niemiec

Technology and Properties of (1-x)PZT-(x)PFW Ceramics with 0.25<x<0.55

We present the results of obtaining and investigating ceramic samples of solid solution (1-x)(PbZr0.53Ti0.47O3)-x (PbFe2/3W1/3O3) [i.e. (1-x)PZT-xPFW] with x = 0.25, 0.35, 0.45 and 0.55 obtained from oxides using conventional ceramic technology. In this paper we present the results of investigations of XRD and main dielectric properties. For x = 0.25 and x = 0.35 we investigated also P-E hysteresis loops at room temperature.

Magnetic properties and phase diagram of (1-x)PZT-(x)PFW ceramics with 0.25<x<0.55

Solid solution (1−x)(PbZr0.53Ti0.47O3)−x(PbFe2/3W1/3O3) [i.e. (1-x)PZT-xPFW] belongs to materials called multiferroics. Such materials are interesting due to their potential practical applications, and also because of the possibility to investigate the basics of physical phenomena occurring in them. We obtained ceramic samples of PZT-PFW from oxides using classic ceramic technology and earlier we studied their basic dielectric properties. In this work we describe the results of investigations magnetic properties which have been made using the QD MPMS-XL-7 SQUID magnetometer. Basing on these measurements of electric and magnetic properties and on the literature data we have constructed extended phase diagram of this solid solution.

Multiferroic Ceramic Composites Based on PZT Type Ceramic and NiZnFe Ferrite

Multiferroic (ferroelectric–ferromagnetic) ceramic composites were obtained on the basis of a ceramic powder of PZT type, i.e. Pb(Zr0.51Ti0.49)O3 + 0.2% at. Bi2O3 + 0.03% at. Nb2O5 + 0.06% at. MnO2 (marked as PZTBNM) and Pb0.84Ba0.16(Zr0.54Ti0.46)O3 + 1.0% at. Nb2O5 (marked as PBZTN). Admixtured compositions constituted of a PZT type ferroelectric powder with nickel-zinc ferrite (Ni1-xZnxFe2O4) as the magnetic content in the composite. Synthesis of the composite content was performed using compact sintering in the solid phase, while densification of the synthesized powder was achieved using the pressure-less sintering method (conventional sintering method). For the obtained multiferroic ceramic composites XRD investigations were performed, as well as investigations of microstructure, EDS, dielectric and magnetic properties, impedance and electrical hysteresis loop. The tests showed the existence of a correlation between magnetic and electric subsystems in the composites. Thanks to the ferroelectric and magnetic properties of the composites obtained, materials of this type could be applied, for example, in new memory types or magnetoelectric transducers.

The properties of (1-x)(0.5PZT-0.5PFW)-xPFN ceramics

ABSTRACT The ceramic samples of solid solution (1-x)[0.5(PbZr0.53Ti0.47O3)-0.5(PbFe2/3W1/3O3)]-x(PbFe1/2Nb1/2O3) [i.e. (1-x)(0.5PZT-0.5PFW)-xPFN] with x = 0; 0.1; 0.2 have been obtained by conventional ceramic technology using the free sintering (FS) method from PbO, ZrO2, TiO2, Fe2O3, WO3 and Nb2O5 oxides. Basing on the literature data for individual components, it can be expected that this material ought to have interesting multiferroic properties. The presented work is the first step in obtaining and investigating this solid solution. In the presented paper, the technology and the results of investigations of EDS, XRD, the microstructure of fractured samples, dielectric permittivity v.s. temperature, and d.c. electric conductivity are presented.

Dispersion of dielectric permittivity and magnetic properties of solid solution PZT–PFT

Abstract In this paper we present the results of investigations into ceramic samples of solid solution (1-x)(PbZr0.53Ti0.47O3)- x(PbFe0.5Ta0.503) (i.e. (1-x)PZT-xPFT) with x = 0.25, 0.35 and 0.45. We try to find the relation between the character of dielectric dispersion at various temperatures and the composition of this solution. We also describe the magnetic properties of investigated samples. With increasing the content of PFT also mass magnetization and mass susceptibility increase (i.e. magnetic properties are more pronounced) at every temperature. The temperature dependences of mass magnetization and reciprocal of mass susceptibility have similar runs for all the compositions. However, our magnetic investigations exhibit weak antiferromagnetic ordering instead of the ferromagnetic one at room temperature. We can also say that up to room temperature any magnetic phase transition has not occurred. It may be a result of the conditions of the technological process during producing our PZT-PFT ceramics.

Diffused AFE/RFE/PE phase transitions in (Pb0.88Ba0.1La0.02)(Zr0.6Sn0.4− x Ti x )0.995O3 ceramics obtained from oxides and carbonates

We present the results of preparation and investigation of antiferroelectric/relaxor/paraelectric (AFE/RFE/PE) phase transitions in ceramics, (Pb0.88Ba0.1La0.02)(Zr0.6Sn0.4− x Ti x )0.995O3 with x = 0.05, 0.055, 0.06, and 0.065, obtained from oxides and carbonates using a conventional ceramic technology. Such compositions can be good candidates for energy storage in pulse capacitors. For such application, the critical field should be appropriate, i.e., neither too high nor too low, since the transition from AFE to FE/RFE properties should take place in fields close to electric breakdown, since in such situation the stored energy is the biggest. We present the results of investigations of the microstructure, dielectric permittivity, and P–E hysteresis loops at various temperatures. It has been stated that some of the investigated materials exhibit field-induced AFE/FE or AFE/RF transition appropriate for application in pulse capacitors.

Microstructure and Properties of the Ferroelectric-Ferromagnetic PLZT-Ferrite Composites

The paper presents the technology of ferroelectric-ferromagnetic ceramic composites obtained from PLZT powder (the chemical formula Pb0.98La0.02(Zr0.90Ti0.10)0.995O3) and ferrite powder (Ni0.64Zn0.36Fe2O4), 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.

Electrophysical Properties of the PMN–PT–PS Solid Solution

The (1 − y) ((1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3)–yPbSnO3 solid solution (PMN–PT–PS) was obtained and investigated in the present paper. For the analysis of the influence of the PbSnO3 component on the electrophysical parameters, the compositions from the rhombohedral phase, tetragonal phase, and a mixture of these phases were selected. The six compositions of the PMN–PT have been obtained using sol–gel methods (for values of x equal to 0.25, 0.28, 0.31, 0.34, 0.37, and 0.40). The ceramic samples of the 0.9(PMN–PT)–0.1(PS) solid solution have been obtained using the conventional ceramic route. X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and microstructure measurements were performed, as well as tests regarding the dielectric, ferroelectric, piezoelectric properties and electric conductivity of the PMN–PT–PS ceramic samples versus temperature. Results of the measurements show that the obtained PMN–PT–PS materials have good electrophysical properties and are well suited for use in micromechatronic and microelectronic applications.

Electrophysical properties of the multicomponent PBZT-type ceramics doped by Sn4+

In the work, the multicomponent Pb0.75Ba0.25(Zr0.65Ti0.35)1-aSnaO3 (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 SnO2 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 SnO2 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 SnO2 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.

Technology and dielectric properties of the PLZT-NZF composites

ABSTRACT The aims of the study were to design and obtain ferroelectric-ferromagnetic ceramic composites based on ferrite powder and PLZT powder. The synthesis of the composition of the PLZT material of chemical formula Pb0.98La0.02(Zr0.90Ti0.10)0.995O3 was carried out by conventional technology. The composite constituted 90% of PLZT powder and 10% of ferrite powder (Ni0.64Zn0.36Fe2O4). The article presents the technology and the results of a XRD measurement, a microstructure and the dielectric properties of the composite samples. This type of multiferroic materials and ferroelectric-ferrimagnetic composites can be used to develop a new class of transducers/sensors integrating electro-magnetic interaction in a single device.