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PZT-Type Ceramics Doped with Manganese, Antimony, Lanthanum and Tungsten - Technology and Physical Properties

Bochenek D., Niemiec P., Ćwikiel E., Goryczka T.

Archives of Metallurgy and Materials

2020

Vol. 65, iss. 2

827--837

The work three ceramic compositions based on PbZr0.49 Ti0.51O3 doped with manganese (Mn), antimony (Sb), lanthanum (La) and tungsten (W) were obtained. The introduction of a set of admixtures was aimed at improving the sinterability of ceramic materials and optimizing its electrophysical parameters. Multi-component materials of the PZT-type with a general formula: Pb(PbZr0.49 Ti0.51)0.94 Mn0.021 Sb0.016 LayWz O3 (where y from 0.008 to 0.012 and z from 0.012 to 0.014) were prepared by the conventional mixed oxide method. After mixing and drying the powder mixtures were calcined in air at 850°C for 4 h, while densification of the powders was carried out by the free sintering method at 1150°C for 2 h. The final steps of technology were grinding, polishing, annealing and putting silver paste electrodes onto both surfaces of the samples for electrical testing. XRD, SEM, EDS, dielectric, ferroelectric, piezoelectric properties and DC electrical conductivity of the obtained ceramic compositions were carried out. X-ray tests of the crystal structure conducted at room temperature have shown that all obtained the PZT-type materials were a single phase (perovskite type) without the presence of a foreign phase. Symmetry of the crystal lattice was identified as space group P4mm. Temperature dielectric studies have shown high values of dielectric permittivity and low dielectric loss. The presented physical properties of ceramic samples based on PZT confirm their predisposition for application in modern microelectronic and micromechatronic applications.

Podstawowe właściwości ceramiki PFN domieszkowanej potasem

Bochenek D., Niemiec P., Cieplik B.

Materiały Ceramiczne

2016

T. 68, nr 1

9--13

W pracy metodą jednoetapowej syntezy otrzymano ceramikę PFN, którą poddano modyfikowaniu potasem w ilości 1,0%, 2,0%, 3,0%, 4,0% i 6,0% mol. Przeprowadzono badania wpływu domieszki potasu na strukturę krystaliczną, mikrostrukturę i podstawowe właściwości ceramiki PFN. Wykazano, że hetrowalencyjne domieszkowanie PFN potasem w ilości od 2,0% mol. do 4,0% mol. wpływa pozytywnie na gęstość i jednorodność mikrostruktury ceramicznych próbek. Domieszka potasu w takiej ilości przyczynia się do ograniczenia powstawania nieferroelektrycznej fazy pirochlorowej podczas procesu technologicznego. Badania dielektryczne domieszkowanych składów wykazały, że potas wywołuje spadek wartości maksymalnej przenikalności elektrycznej i zmniejsza nieznacznie stopień rozmycia przemiany fazowej. Zwiększeniu ulegają także straty dielektryczne oraz przewodnictwo elektryczne. Nie zaobserwowano jednoznacznej tendencji wpływu wprowadzanej domieszki potasu na podstawowe parametry ceramiki PFN.

In the work, PFN ceramics were obtained by a one-step synthesis. The ceramics were modified with the help of potassium incorporated in an amount of 1.0%, 2.0%, 3.0%, 4.0% and 6.0 mol%. Effects of the potassium dopant on the crystal structure, microstructure and main properties of the PFN ceramics were studied. It has been shown that the heterovalence doping of PFN by the potassium in the amount of 2.0-4.0 mol%. had a positive effect on the density and microstructural homogeneity of the ceramic samples. Such a potassium admixture limited the formation of the non-ferroelectric (pirochlore) phase during the technological process. Measurements of dielectric properties of the doped compositions have shown that potassium causes a decrease of the maximum permittivity and reduces slightly the degree of blur of the phase transition. There is also an increase in the dielectric loss and electrical conductivity. There was no a clear trend in the effect of the incorporated potassium additive on the basic parameters of the PFN ceramics.