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1
Content available X-Ray Diffraction Study of Bismuth Layer-Structured Multiferroic Ceramics
Lisińska-Czekaj A., Czekaj D., Garbarz-Glos B., Bąk W., Kuźniarska-Biernacka I.
Archives of Metallurgy and Materials
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2020
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Vol. 65, iss. 2
811--815
EN
Goal of the present research was to apply a solid state reaction route to fabricate bismuth layer-structured multiferroic ceramics described with the formula Bi5FeTi3O15 and reveal the influence of processing conditions on its crystal structure and phase composition. Simple oxide powders Bi2O3, TiO2 and Fe2O3 were used to fabricate Aurivillius-type bismuth layer-structured ferroelectrics. Pressureless sintering in ambient air was employed and the sintering temperature was TS = 900°C, TS = 1000°C and TS = 1040°C. The phase composition as well as crystal structure of ceramics sintered at various processing conditions was examined with powder X-ray diffraction method at room temperature. The Rietveld refinement method was applied for analysis of X-ray diffraction data. It was found that ceramics adopted orthorhombic structure Cmc21. The unit cell parameters of bismuth layer-structured multiferroic ceramics increased slightly with an increase in sintering temperature.
2
Content available The Application of the Mechanochemical Synthesis for the Preparation of Advanced Ceramics Based on Barium Titanate
Garbarz-Glos B., Bąk W., Budziak A., Dulian P., Lisińska-Czekaj A., Czekaj D.
Archives of Metallurgy and Materials
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2020
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Vol. 65, iss. 4
1391--1396
EN
In the present study, the lead-free BaTi1-x Zrx O3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to 10 MHz. The obtained measurement data, analyzed in accordance with the Arrhenius formalism demonstrated the presence of relaxation type dielectric mechanisms. The impedance answer of studied ceramic materials indicated the presence of two relaxation processes: one with a dominant resistive component and the other with a small capacitive component. The observed dielectric relaxation process is temperature dependent and has a “non-Debye” character.
3
Content available Modelling of Dielectric Properties of BiNbO4-Based Microwave Ceramics
Czekaj D., Lisińska-Czekaj A., Garbarz-Glos B., Bąk W.
Archives of Metallurgy and Materials
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2020
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Vol. 65, iss. 3
1177--1181
EN
In the present paper results of the studies devoted to computer simulations of dielectric response of electroceramics in a frequency domain as well as analysis of the experimental data are given. As an object of investigations BiNbO4-based microwave ceramics was taken. Simulations of the hypothetical impedance response of the ceramic system were performed under assumption of the brick-layer model. A strategy for analysis and modelling of the impedance data for microwave electroceramics was discussed. On the base of the discussed strategy modelling of the dielectric response of BiNbO4 ceramics was performed with the electric equivalent circuit method. The Voigt’s and Maxwell’s circuits were taken as electric models. Parameters of the electric components of the circuits were determined and related to parameters of the ceramic object under study. It was found that fitting quality was good and changed within the range χ2 = 6.78 × 10-4 – 6.77 × 10-5 depending on the model.
4
Content available Alternative, Direct Synthesis Method of the Ceramic Solid Solutions Based on BaTiO3 Through a High Energy Ball Milling
Bąk W., Dulian P., Garbarz-Glos B., Czekaj D., Lisińska-Czekaj A.
Archives of Metallurgy and Materials
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2020
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Vol. 65, iss. 2
805--810
EN
Polycrystalline samples BaTiO3 and the solid solutions Ba0.9 Sr0.1 TiO3, 0.9 Sr0.1 Ti0.9 Sn0.1 O3, Ba0.9 Sr0.1 Ti0.8 Sn0.2 O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure and morphology of the investigated samples were characterized by an X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterization of electrical properties of the ceramics within the temperature range from –130°C to 250°C were performed by means of a dielectric spectroscopy method at the frequency ranging from 0.1 Hz to10 MHz. The diffusion of the paraelectric – ferroelectric phase transition and dielectric relaxation for ceramic samples are described.
5
Content available remote Właściwości dielektryczne materiałów ceramicznych otrzymanych na bazie TiO2
Bąk W., Dulian P., Garbarz-Glos B., Żukowski W., Kajtoch C.
Materiały Ceramiczne
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2017
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T. 69, nr 4
370--373
PL
Domieszkowane jonami donorowymi (Nb5+, V5+) i akceptorowymi (In3+) próbki TiO2 (rutyl) otrzymano konwencjonalną metodą reakcji w stanie stałym. Strukturę badanych próbek scharakteryzowano przy pomocy analizy XRD. Właściwości dielektryczne próbek zbadano w zakresie temperatur od -100 stopni C do 200 stopni C przy pomocy szerokopasmowej spektroskopii dielektrycznej w zakresie częstotliwości pola elektrycznego od 0,1 Hz do 10 MHz. Analiza zależności temperaturowych przenikalności dielektrycznej, przewodnictwa i modułu elektrycznego dostarczyła nowych informacji na temat właściwości fizycznych badanych materiałów ceramicznych.
EN
Doped with donor (Nb5+, V5+) and acceptor (In3+) ions TiO2 (rutile) was obtained by the conventional solid state reaction method. The structure of the investigated samples was characterised by X-ray diffraction (XRD). The dielectric properties of the samples at the temperature ranging from -100 C to 200 C was studied by means of the broadband dielectric spectroscopy method at the frequency ranging from 0,1 Hz to 10 MHz. An analysis of the temperature dependences of dielectric permittivity, electric modulus and conductivity provided new details about the physical properties of the ceramic samples.
6
Content available Low temperature broad band dielectric spectroscopy of multiferroic Bi6Fe2Ti3O18 ceramics
Lisińska-Czekaj A., Rerak M., Czekaj D., Lubina M., Garbarz-Glos B., Bąk W.
Archives of Metallurgy and Materials
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2016
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Vol. 61, iss. 3
1447--1452
EN
In the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18is (BFTO) Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz - 10MHz) within the temperature range ΔΤ=-100°C - 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found that the measured impedance data exhibited good quality justifying further analysis. The residuals were found to be less than 1%, whereas the "chi-square" parameter was within the range χ2~-10-7 -10-5. Experimental data were analyzed using the circle fit of simple impedance arc plotted in the complex Z”-Z` plane (Nyquist plot). The total ac conductivity of the grain boundaries was thus revealed and the activation energy of ac conductivity for the grain boundaries was calculated. It was found that activation energy of ac conductivity of grain boundaries changes from ΕA=0.20eV to ΕA=0.55eV while temperature rises from Τ=-100°C up to Τ=200°C. On the base of maxima of the impedance semicircles (ωmτm=l) the relaxation phenomena were characterized in terms of the temperature dependence of relaxation times and relevant activation energy was calculated (ΕA=0.55eV).
7
Content available Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
Bąk W., Kajtoch C., Ptaszek S., Lisińska-Czekaj A., Czekaj D., Ziętek D., Glos T., Garbarz-Glos B.
Archives of Metallurgy and Materials
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2016
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Vol. 61, iss. 2A
905--908
EN
The results of the microstructural and dielectric measurements of (Ba1-xPbx)(Ti1-xSnx)O3 (BPTSx) (x = 0, 0.05, 0.10, 0.30) polycrystalline samples are presented. The samples were obtained by means of a high temperature synthesis and their expected stoichiometry was confirmed by energy dispersive spectroscopy (EDS) measurements. The dielectric properties of BPTSx were studied with the use of broadband dielectric spectroscopy. The measurements over a wide range of temperature (from 140 K to 600 K) and frequency (from 0.1 Hz to 10 MHz) were performed. The experimental results indicate an influence of Pb ions in a sublattice A and Sn ions in a sublattice B substitution on paraelectric - ferroelectric phase transition parameters. Diffused phase transitions from a paraelectric to ferroelectric state (for x = 0.10 and x = 0.30) were observed. From the electric modulus measurements in the frequency domain the relaxation times and the activation energy were determined.
8
Content available Influence of Processing Conditions on Crystal Structure of Bi6Fe2Ti3O18 Ceramics
Lisińska-Czekaj A., Lubina M., Czekaj D., Rerak M., Garbarz-Glos B., Bąk W.
Archives of Metallurgy and Materials
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2016
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Vol. 61, iss. 2A
881--886
EN
Aim of the present research was to apply a solid state reaction route to fabricate Aurivillius-type ceramics described with the formula Bi6Fe2Ti3O18 (BFTO) and reveal the influence of processing conditions on its crystal structure. Pressureless sintering in ambient air was employed and the sintering temperatures were 850 and 1080 °C. It was found that the fabricated BFTO ceramics were multiphase ones. They consisted of two Bim+1Fem-3Ti3O3m+3 phases, namely the phase with m=5 (i.e. the stoichiometric phase) and m=4 (i.e. the phase with a reduced number of layers in the slab). Detailed X-ray diffraction patterns analysis showed that both phases adopted the same orthorhombic structure described with Fmm2 (42) space group. The ratio of weight fractions of the constituent phases (m=5): (m=4) was ~30:70.
9
Content available Effect of Semiconductor Element Substitution on the Electric Properties of Barium Titanate Ceramics
Garbarz-Glos B., Lisińska-Czekaj A., Czekaj D., Bąk W.
Archives of Metallurgy and Materials
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2016
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Vol. 61, iss. 2A
887--890
EN
The investigated ceramics were prepared by a solid-state reaction from simple oxides and carbonates with the use of a mixed oxide method (MOM). The morphology of BaTi0.96Si0.04O3 (BTSi04) ceramics was characterised by means of a scanning electron microscopy (SEM). It was found that Si+4 ion substitution supported the grain growth process in BT-based ceramics. The EDS results confirmed the high purity and expected quantitative composition of the synthesized material. The dielectric properties of the ceramics were also determined within the temperature range (ΔT=130-500K). It was found that the substitution of Si+4 ions had a significant influence on temperature behavior of the real (ε’) and imaginary (ε”) parts of electric permittivity as well as the temperature dependence of a.c. conductivity. Temperature regions of PTCR effect (positive temperature coefficient of resistivity) were determined for BTSi04 ceramics in the vicinity of structural phase transitions typical for barium titanate. No distinct maximum indicating a low-temperature structural transition to a rhombohedral phase in BTSi04 was found. The activation energy of conductivity was determined from the Arrhenius plots. It was found that substitution of Si ions in amount of 4wt.% caused almost 50% decrease in an activation energy value.
10
Content available remote Wpływ koncentracji litu na wybrane właściwości strukturalne i mechaniczne ceramicznych stałych roztworów Na(1-x)Li(x)NbO3 dla x ≤ 0,06
Śmiga W., Piekarczyk J., Garbarz-Glos B.
Materiały Ceramiczne
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2006
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R. 58, nr 3
96-101
PL
W pracy przedstawiono wyniki badań mikrostruktury, stałych materiałowych (E, G, v), twardości Vickersa i odporności na kruche pękanie w zależności od koncentracji litu w próbkach Na(1-x)Li(x)NbO3 dla x ≤ 0,06. Polikrystaliczne próbki otrzymano metodą klasyczną, stałe materiałowe wyznaczono metodą ultradźwiękową. Dodatek litu do niobianu sodu NaNbO3 powoduje wyraźne zmniejszenie prędkości fal ultradźwiękowych, modułu Younga, modułu sztywności G, współczynnika K(ic) i twardości. Największe obniżenie właściwości mechanicznych występujące przy 2% mol litu w NaNbO3, można wiązać się z występowaniem w stałym roztworze Na(1-x)Li(x)NbO3 granicy morfotropowej dla tego stężenia. Nie stwierdzono systematycznej zależności porowatości od stężenia litu.
EN
In the paper the results of the investigation on microstructure, material constants (E, G, v), Vickers' hardness and facture toughness depending on concentration of lithium in Na(1-x)Li(x)NbO3 samples for x ≤ 0.06 were presented. Polycrystalline samples were obtained with the classical method, material constants were determined using the ultrasonic method. The addition of lithium to sodium niobate NaNbO3 causes an evident decrease of the velocity of ultrasonic waves, Young's modulus, shear modulus G, K(ic) coefficient and hardness. The highest deterioration of mechanical properties appearing at 2 mol-percent of lithium in NaNbO3 can be related to the occurrence in NaNbO3 solid solution a morthotrophic limit for this concentration. No systematic dependence of the porosity on the concentration of lithium.
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