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1

Podstawowe właściwości ceramiki PFN domieszkowanej potasem

Bochenek D., Niemiec P., Cieplik B.

Materiały Ceramiczne

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2016

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T. 68, nr 1

9--13

PL

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.

EN

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.

2

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

Skulski R., Niemiec P., Bochenek D., Chrobak A.

Materials Science Poland

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2015

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Vol. 33, No. 3

497--500

EN

In this paper we present the results of investigations into 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. 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.

3

Technology and properties PMN-PT-PS-PFN:LI material for multilayer capacitor

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

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 4

1313--1316

EN

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.

PL

W pracy zaprojektowano i otrzymano wieloskładnikowy materiał o wzorze 0.6075PMN-0.2025PT-0.09PS-0.1PFN:Li (PMN-PT-PS-PFN:Li) dla zastosowań na podłoża do wielowarstwowych kondensatorów MLCC. Otrzymywanie materiału PMN-PT-PS-PFN:Li było prowadzone dwiema metodami syntetyzowania. W pierwszej metodzie do otrzymania PMN-PT-PS- PFN:Li zastosowano syntetyzowanie prostych związków (tlenki, węglany), w drugiej metodzie zastosowano syntetyzowanie złożonych związków (MgNb2O6 i FeNbO4), oraz prostych związków (tlenków PbO, TiO2 i węglanu Li2CO3). Z syntetyzowanego proszku materiału PMN-PT-PS-PFN:Li otrzymano ceramiczne próbki które zostały poddane kompleksowym badaniom. Przeprowadzono badania rentgenowskie, mikrostrukturalne oraz ferroelektrycznych, dielektrycznych i sprężystych właściwości.

4

Fabrication and properties of multilayer capacitors with multicomponent ferroelectric dielectric

Kulawik J., Szwagierczak D.

Elektronika : konstrukcje, technologie, zastosowania

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2012

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Vol. 53, nr 4

25-27

EN

Tape casting and LTCC technology were used for fabrication of multilayer capacitors with 0.26Pb(Mg1/3Nb2/3)O₃-0.26Pb(Zn1/3Nb2/)O₃-0.26Pb (Fe2/3W1/3)O₃-0.14Pb(Fe1/2Nb1/2)O₃-0.08BaTiO₃ dielectric layers. The organic part of a slip comprises polyvinyl butyral as a binder, fish oil as a dispersant, polyethylene glycol and dibutyl phthalate as plasticizers, toluene and isopropyl alcohol as solvents. Test multilayer capacitors containing 30 green tapes 50 μm thick were fired at 850°C. Impedance spectroscopic studies of capacitors were carried out in the temperature range from -55 to 440°C at frequencies 10 Hz - 2 MHz. Microstructure of the dielectric layers and their compatibility with Ag electrodes were studied using a scanning electron microscope. The multilayer ceramic capacitors exhibit high capacitance reaching 1 μF and relatively low temperature coefficient of capacitance. There are two high and broad maxima in the temperature dependence of dielectric permittivity - the first one related to the ferroelectric transition at 40°C and the second one attributed to dielectric relaxation which occurs in the temperature range 190-440°C.

PL

Zastosowano technologię odlewania folii i technologię LTCC do wytwarzania wielowarstwowych kondensatorów z dielektrycznymi warstwami o składzie 0.26Pb(Mg1/3Nb2/3)O₃-0.26Pb(Zn1/3Nb2/)O₃-0.26Pb (Fe2/3W1/3)O₃-0.14Pb(Fe1/2Nb1/2)O₃-0.08BaTiO₃. Część organiczna gęstwy do odlewania folii zawiera poliwinylobutyral jako spoiwo, ftalan dwubutylu i glikol polietylenowy jako zmiękczacze, olej rybi jako dyspersant oraz toluen i alkohol izopropylowy jako rozpuszczalniki. Testowe wielowarstwowe kondensatory złożone z 30 surowych warstw o grubości 50 μm wypalono w temperaturze 850°C. Przeprowadzono badania kondensatorów metodą spektroskopii impedancyjnej w zakresie temperatur -55...440°C i w zakresie częstotliwości 10 Hz - 2 MHz. Przy użyciu mikroskopu skaningowego badano mikrostrukturę warstw dielektrycznych i ich kompatybilność z elektrodami Ag. Wielowarstwowe ceramiczne kondensatory wykazują wysoką pojemność sięgającą 1 μF i relatywnie niski temperaturowy współczynnik pojemności. Na temperaturowej zależności przenikalności elektrycznej występują dwa wysokie i szerokie maksima - pierwsze związane z ferroelektryczną przemianą w temperaturze 40°C i drugie, które można przypisać dielektrycznej relaksacji, występujące w zakresie temperatur 190...440°C.

5

Technology, physical properties and phase transitions in PMN-PT-PS ceramics

Skulski R., Bochenek D., Wawrzała P.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 4

1051-1056

EN

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.

PL

Opisany w tej pracy roztwór stały (1-y)[(1-x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3]-yPbSnO3 (PMN-PT-PS) jest oparty na roztworze (1-x)PMN-xPT (PMN-PT) w którym, w zależności od składu ma miejsce przejście od właściwości relaksorowych do ferroelektrycznych ze wzrastającym x. Ceramika PMN-PT z 0,25< x <0,4 została otrzymana metodą zolowo-żelowa, a następnie wymieszana z ceramika PS otrzymana z tlenków. Końcowe spiekanie było spiekaniem swobodnym. Przedstawiamy rezultaty badań mikrostruktury, badań rentgenowskich, zależności przenikalności dielektrycznej i pętli histerezy dielektrycznej od temperatury.

6

Study of the relaxor behaviour in Ba0.68Na0.32Ti0.68Nb0.32O3 ceramic

Bąk W.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 1

24-27

EN

Purpose: The purpose of this work was to synthesize a new ceramic solid solution Ba0.68Na0.32Ti0.68Nb0.32O3 (BNTN32), as well as to measure and analyse its dielectric properties within the temperature range 123 K-473 K, where dielectrically active phase transition was supposed to occur. Design/methodology/approach: The new ceramic composition was prepared by means of conventional method. Dependence of phase transition features on temperature and frequency of measuring field were measured using dielectric spectroscopy method within the frequency range from 20 Hz to 1 MHz. Findings: The electric susceptibility along with temperature decrease generally rises up and has transient dispersion vanishing at about 230 K. At higher and low temperatures, frequency dependence of dispersion differs in character: at temperatures at ~400 K, low frequency values dominate. Dielectric energy losses are very high at ~high temperature, they decline down while temperature decrease, and at about 200 K range its frequency dependence is reversed and less scattered with maximum at ~150 K. The whole transition of ferroelectric - paraelectric (FE - PE) type can be described by means of Curie-Weiss law and it gets diffused character. Research limitations/implications: For modelling purposes the structure parameters of BNTN32 have to be measured by X-ray diffraction in order to establish the dielectric/structural activities of transitions taking place within used the temperature range. Additionally, dielectric measurements within broader frequency range up to 1.8 GHz will be performed. Originality/value: The new type of ceramic material was prepared with interesting dielectric properties. Dispersion reverse of energy losses activated thermally and low frequency memory of barium titanate (BT) transition effect visible at ~400 K is to be a subject of modelling further work.

7

The Electrical Conductivity of PMN-PT Ceramics

Skulski R., Wawrzała P., Szymonik M.

Archives of Metallurgy and Materials

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2009

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Vol. 54, iss. 4

935-941

EN

The results of investigations of d.c. and a.c. conductivity are presented for PMN-PT ceramics obtained by two step sol-gel method. A.c. conductivity has been calculated from dielectric measurements for frequencies 100Hz-20kHz. It has been stated that the activation energy calculated from d.c. conductivity is much higher than calculated from a.c. conductivity. The analysis based on Jonsher’s power law is also presented.

PL

W pracy przedstawiono wyniki badań przewodnictwa stałopradowego i zmiennopradowego dla ceramiki PMN-PT otrzymanej dwustopniową metodą zol-żel. Przewodnictwo zmienno prądowe było obliczane na podstawie pomiarów dielektrycznych w przedziale częstotliwości 100Hz-20kHz. Stwierdzono, że energia aktywacji obliczona z pomiarów przewodnictwa stałoprądowego jest znacznie wyższa, niż obliczona z przewodnictwa zmiennoprądowego. Przedstawiono również analizę w oparciu o uniwersalne prawo potęgowe Jonshera.

8

The dielectric behaviour of polycrystalline Ba0.96Na0.04Ti0.96Nb0.04O3 solid solution

Bąk W., Gabryś M., Kajtoch C., Tejchman W., Starzyk F.

Archives of Materials Science and Engineering

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2009

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Vol. 40, nr 1

13-16

EN

Purpose: The purpose of this work was to measure and investigate dielectric properties of new material, polycrystalline solid solution Ba0.96Na0.04Ti0.96Nb0.04O3 (BNTN4) within the temperature range 153 K-473 K. Design/methodology/approach: The dielectric spectroscopy method has been applied to measure dielectric and electric parameters within the frequencies from 20 Hz to 1 MHz. Findings: The dielectric permittivity (&epsilon') dependence on temperature (T) within the range of 473 K-225 K consist of two components: the reversly proportional one and the second one in the form of small local, transient peak at about 400 K. The global maximum is frequency dependent and above &sim 400 K along the T decrease, the dispersion of &epsilon' is initiated and low frequency dispersion of &epsilon' prevails below 250 K. Energy losses measure (&epsilon"), correlated with &epsilon'(T), is generally shifted towards lower T values. Its frequency dependence undergoes inversion which develops with T decrease and is initiated at about 370 K. The whole temperature induced phase transition turned out to be of relaxor kind and diffused process. The detailed analysis of this transition and its features was performed. Research limitations/implications: In order to determine the details of polycrystalline structure of BNTN4 new material for modelling of ferroelectric properties the precise X-ray diffraction measurements should be performed as function of T. The nature of ferroelectric - paraelectric (FE - PE) transition diffusive character will be studied by means of dielectric measurements within frequency range 1 MHz-1.8 GHz. Originality/value: The new kind of ferroelectric solid solution (BNTN4) was synthesized. The specific features of this material at low T range involves among others, the T-dependent dispersion of dielectric properties on low T side of broad &epsilon'(T) peak.

9

Study of phase transition specific in polycrystalline Pb(Cd1/3Nb2/3)O3

Kajtoch C., Bąk W., Starzyk F., Gabryś M.

Archives of Materials Science and Engineering

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2008

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Vol. 29, nr 1

20-23

EN

Purpose: of this paper was to isolate and attempt to identify experimentally specific features of paraelectric diffused phase of Pb(Cd1/3Nb2/3)O3 (PCN) not reported yet in the literature. Design/methodology/approach: we used was to measure and analyse the temperature and frequency dependence of polarization, energy loss, phase angle and ac-conductivity components. Findings: we have isolated four specific processes visible as specific behaviour of ĺ’(T, í); on ĺ” and phase angle also temperature and frequency dependences and three contributions to ac-conductivity. Practical implications: processes isolated will be used to construct a model of polarizability and energy loss as well as ac-conductivity in diffused paraelectric phase of PCN. Originality/value: of the paper rely on the possibility of experimental verification of temperature induced evolution of polar regions structure and dynamics created in high temperature region of paraelectric phase of PCN.

10

Relaxor properties of Ba1-xNaxTi1-xNbxO3 at low temperatures

Bąk W.

Archives of Materials Science and Engineering

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2008

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Vol. 34, nr 1

23-26

EN

Purpose: The purpose of this paper is to investigate ferroelectric relaxor behavior of polycrystalline solid solutions of Ba1-xNaxTi1-xNbxO3 (for x = 0.3 and x = 0.4) at low temperatures (113 K - 473 K). Design/methodology/approach: The dielectric spectroscopy method has been applied to measure dielectric and electric parameters within the frequencies from 20 Hz to 1 MHz. Findings: Temperature dependences of real (ε') and imaginary (ε'') parts of dielectric permittivity confirm relaxor type of polarization behavior for both investigated materials. Experimental findings are in good agreement with data published in literature. Diffused phase transition of relaxor character is analysed in the terms of departure from Curie-Weiss rule. A dependence of the temperature related to the maximum of dielectric permittivity on the frequency has activated character. Different thermal activation energies found for the investigated materials may be related to their different microstructures. Research limitations/implications: Further investigations should be carried on in a broaden frequency range (up to 1.8 GHz) in order to establish an influence of network dynamics on ferroelectric-paraelectric phase transition. Originality/value: Relaxor behaviour in polycrystalline solid solution of Ba1-xNaxTi1-xNbxO3 (for x = 0.3 and x = 0.4) is described.

11

Elevated temperature induced dispersion phenomena in Ba1-xNaxTi1-xNbxO3

Bąk W., Starzyk F., Kajtoch C., Nogas-Ćwikiel E.

Archives of Materials Science and Engineering

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2008

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Vol. 29, nr 1

5-9

EN

Purpose: of this paper was to investigate features of the dispersion of dielectric permittivity induced by elevated temperature (473K-723K) in polycrystalline solid solution of Ba1-xNaxTi1-xNbxO3 (for x=0.3 and x=0.4). Design/methodology/approach: used to perform this purpose was dielectric spectroscopy application to measure dielectric and electric parameters within the frequency range (20Hz-1MHz). Findings: Analysis of temperature and frequency dependences of real (ĺ’) and imaginary (ĺ”) parts of dielectric permittivity had pointed out on relaxor type of dielectric behaviour for both investigated samples in paraelectric phase. The thermal activation energy values of ac conductivity (for 100Hz) are similar to those of semiconductors. Values of ĺ’ for both materials (x=0.3, x=0.4) are consistent with literature quotations. Thus the polarisation behaviour of our materials seems to be similar to those described in the literature. Different behaviour of dielectric energy losses is postulated as originating from differences of samples microstructure. Research limitations/implications: Further investigations should be carried out in the range of low temperatures (down to 100K) and within a broaden frequency range (up to 1.8GHz) in order to establish the influence of chemical structure on ferroelectric-paraelectric phase transition. Originality/value: Dielectric properties for two new material prepared from nanopowders of BaTiO3 and NaNbO3 were described.

12

Badanie warunków otrzymywania i właściwości ceramiki Pb(Zn1/3Nb2/3)O3-BaTiO3-PbTiO3 o wysokiej stałej dielektrycznej.

Szwagierczak D., Kulawik J., Gandurska J., Marek A., Śnieżyńska I.

Szkło i Ceramika

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2003

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R. 54, nr 1

32-37

PL

Badano wpływ warunków kalcynacji wyjściowych proszków i spiekania ceramiki na właściwości dielektryczne materiałów w układzie Pb(Zn1/3Nb2/3)O3-BaTiO3-PbTiO3. Wyznaczono stałą dielektryczną i współczynnik stratności w zakresie temperatur od -55 do 160 stopni Celsjusza i częstotliwości 10 Hz-1 MHz oraz rezystywność w zakresie temperatur 20-500 stopni Celsjusza. Otrzymana ceramika po spiekaniu w temperaturze 1150 stopni Celsjusza charakteryzowała się maksymalną wartością stałej dielektrycznej 6200-10600 przy częstotliwości 1 kHz, temperaturą Curie 40-85 stopni Celsjusza, wysoką rezystywnością w temperaturze pokojowej 1014-1015 Omega cm. Energia aktywacji przewodnictwa wynosiła 0,7-1,2 eV.

EN

The influence of the calcination conditions of starting powders and the sintering conditions of ceramics on dielectric properties of materials in Pb(Zn1/3Nb2/3)O3-BaTiO3-PbTiO3 system was investigated. Dielectric constant and dissipation factor in the temperature range from -55 to 160 degrees centigrade at frequency 10 Hz-1 MHz as well as resistivity in the temperature range 20-500 degrees centigrade were determined. The obtained ceramics after sintering at 1150 degrees centigrade exhibit maximum values of dielectric constant of 6200-10600 at 1 kHz, Curie temperatures 40-85 degrees centigrade, high resistivities 1014-1015 Omega cm. Activation energy of electrical conductivity was 0,7-1,2 eV.