# Electrophysical Properties of PZT-Type Ceramics Obtained by Two Sintering Methods
## 2 Experiment  
The research material was a PbZr\({}_{x}\)Ti\({}_{1.4}\)O\({}_{3}\) solid solution from the morphotropic region doped with manganese, antimony, gadolinium, and tungsten ions. In this way, a multicomponent PZT material was obtained with the chemical formula: Pb(Zr\({}_{0.49}\)Ti\({}_{0.51}\))\({}_{0.94}\)Mn\({}_{0.021}\) Sb\({}_{0.016}\)Gd\({}_{0.012}\)W\({}_{0.012}\)O\({}_{3}\) (labeled as S). For the synthesis of S material, PbO (99.99%, POCH, Gliwice, Poland), ZrO\({}_{2}\) (99.00%, Merck, Darmstadt, Germany), TiO\({}_{2}\) (99.99%, Merck, Darmstadt, Germany), MnO\({}_{2}\) (99.00%, Aldrich, St. Louis, MO, USA), Sb\({}_{2}\)O\({}_{3}\) (99.99%, Aldrich, St. Louis, MO, USA), Gd\({}_{2}\)O\({}_{3}\) (99.90%, Sigma-Aldrich, St. Louis, MO, USA), WO\({}_{3}\) (99.90%, Sigma-Aldrich, St. Louis, MO, USA) were used. The PbO powder was weighed with a 5 wt.% allowance to compensate for lead evaporation in the sintering process. Starting powders, weighed with stoichiometry, were wet ground (in ethyl alcohol) in a planetary mill (Fritsch Pulverisette 6, Idar-Oberstein, Germany) for 24 h. In the next technological step, powders were dried and calcined at 850 \({}^{\circ}\)C/4 h. Powder S material was pressed into compacts with a diameter of 10 mm on a hydraulic press at a pressure of 300 MPa. In the technological process, sintering powders were performed using two following methods: (i) pressureless sintering (PS) under the following conditions: 1150 \({}^{\circ}\)C/2 h, heating rate 150 \({}^{\circ}\)C/h (labeled as S-PS), (ii) hot pressing (HP) under the following conditions: 1100 \({}^{\circ}\)C/1 h/10 MPa, heating rate 150 \({}^{\circ}\)C/h (labeled as S-HP). Then, the ceramic samples were polished (up to a diameter of 10 mm and a thickness of 1 mm), annealed at 650 \({}^{\circ}\)C for 15 min, and silver paste was applied to the surface of the ceramic samples.  
The X-ray tests (at room temperature) were performed using an X'Pert Pro diffractometer (Panalytical, Eindhoven, the Netherlands) in steps-scan mode: 0.05\({}^{\circ}\) (4 s/step), angular range (20) from 10 to 80\({}^{\circ}\) (copper radiation CuK\({}_{\alpha}\), \(\lambda\) = 1.54178 A). Scanning electron microscopy (SEM), JSM-7100 FTTL LV (Jeol Ltd., Tokyo, Japan) was used to study the microstructure and chemical composition (analyzed by EDS) of the ceramic samples. The average grain size in the microstructure of the ceramic samples was estimated in the ImageJ program. The QuadTech 1920 Precision LCR meter (Maynard, MA, USA) was applied to measure the dielectric properties in the temperature range from 20 to 500 \({}^{\circ}\)C and the frequency range from 20 Hz to 1 MHz. The Keithley 6517B electrometer (Cleveland, OH, USA) measured the DC electric conductivity from 20 to 400 \({}^{\circ}\)C in the temperature range. The _P-E_ tests were conducted using a Sawyer-Tower circuit and the high voltage amplifier Matsusada Inc. HEOPS-5B6 Precision (Kusatsu, Japan) at room temperature (5 Hz) and with a temperature range from 22 to 110 \({}^{\circ}\)C. Measurement data were obtained by using the NI USB-6002 digital card (National Instruments Corporation, Austin, TX, USA) and the LabVIEW program.