Wydział Nauk Ścisłych i Przyrodniczych (WMFT): Recent submissions
Now showing items 441-460 of 944
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Optyczne metody diagnostyki plazmy
(1990)The application to the atomic spectroscopy of the electric arc plasma is described. The states of plasma equilibrium are discussed. A method of the precise evaluation of the line profile (or the total intensity), corrected ... -
Zależność struktury kryształów typu A B od ładunków efektywnych rdzeni atomowych
(1990)The concept of electronegativity was used in this work to analyze the stability of AB type crystalline structures. The parameters of the dependence between ion energy and the charge were adjusted applying a new method. The ... -
Termodynamiczne aspekty przejść fazowych ferroelektryk-paraelektryk
(1990)This work is a theoretical introduction to the problem of the phenomenology of phase transition. A particular attention was paid to the characterization of ferroelectric transitions of the kind of order-disorder. The ... -
Charakterystyki prądowo-napięciowe ferroelektryków
(1990)The review of the most important theoretical considerations explaining the shape of I-V characteristics for ferroelectric materials is done. The assumptions and calculations proposed by Fridkin-Kreher and Krapivin-Chensky ... -
Dielektryczne własności tytanianu sodowo-bizmutowego Na[0.5]Bi[0.5]TiO[3]
(1990)The experiments were carried out on dielectric ceramic sodium – bismuth titonate for some frequence of the applied electric field. The effect of the applied constant electric field on the shift temperature of the phase ... -
Fotoferroelektryczne zjawiska w monokryształach $(Ba, Sr) Nb_2O_6$
(1990)Influence of illumination on phase transition temperature, on dielectric permittivity and on pyro currents in $Ba_xSr_{1-x}Nb_2O_6$ was studied. Dependence of photoelectretic charge density on temperature in the region of ... -
Własności dielektryczne monokryształów $Pb(Cd_{1/3}Nb_{2/3})O_3$
(1990)The temperaturę dependence of ε and tgδ was investigated for monocrystalline sample of $Pb(Cd_{1/3}Nb_{2/3})O_3$ various measurement field frequencies. A strong connection between dielectric properties and field frequency ... -
Przejście fazowe antyferroelektryk - paraelektryk w niestechiometrycznym $NaNbO_3$
(1990)The theory of AFE-PE phase transformation as formulated by Kittel is reviewed. The experimental values obtained from dielectric measurements are related, to the parameters of Kittel's thermodynamic function. Some of the ... -
Klasyfikacja stałych roztworów na bazie $NaNbO_3$
(1990)The criterion of division solid solutions, based on sodium niobate in to ferro-, and antiferroelectric materials is described. The results of measurements are compiled in the table. -
Zmiany temperaturowe współczynnika rozszerzalności liniowej $NaNbO_3$
(1990)The operation principle of a dilatometer is described. The temperature changes of the coefficient of linear expansion were measured in temperature range between minus 196°C and plus 740°C. Linear expansion coefficient ... -
Effect of compressive stress on dielectric and ferroelectric properties of 0.25PSN-0.75PLuN ceramics
(2003)The PSN-PLuN solid solutions have been prepared in the whole composition range for the first time. The dielectric, pyroelectric and hysteresis loops measurements of the 0.25PSN-0.75PLuN ceramics stress-free or under the ... -
Electric properties of polycrystalline $PbCd_{1/3}Ta_{2/3}O_3$
(1999)The temperature dependence of linear expansion, electric permittivity and electric conductivity has been investigated in the region of the diffuse phase transition. The electric properties of polycrystalline $PbСd_{1/3 ... -
Electrical properties of $Na_{0.98}Li_{0.02}NbO_3$ under axial pressure in phase transition region
(2003)The measurements of electric properties of $Na_{0.98}Li_{0.02}NbO_3$ ceramics for stress-free or samples under stress have been carried out. It was found that incorporation of Li-cations (2% mol) in antiferroelectric ... -
Investigation of dielectric properties of $Li_xNa_{1−x}NbO_3$ ceramics for x = 1 and x = 4
(1999)The a.c. electrical response of $Li_xNa_{1−x}NbO_3$ (LNN) solid solution in low frequency range (100 Hz–20 kHz) has been analysed as a function of temperature (300 K–750 K). A complex picture of the dependence of the ... -
The frequency measurements of dielectric properties in the phase transition range in the $Li_{0.02}Na_{0.98}NbO_3$
(1999)Measurement of the temperature, time and frequency changes of dielectric permittivity and dielectric loss in polycrystalline $Li_{0.02}Na_{0.98}NbO_3$ have been carried out. The dielectric permittivity ε has been measured ... -
Dielectric properties of $Li_{0.003}Na_{0.997}NbO_3$ ceramics
(1998)Temperature, frequency and time dependencies of dielectric permittivity and pyroelectric current of $Li_{0.003}Na_{0.997}NbO_3$ ceramics have been presented. Investigation of the pyroeffect reveals the existence of the ... -
Temperature and time changes electric permittivity in sodium niobate
(1997)Temperature and time dependencies of electric permittivity of sodium niobate have been measured. The dispersion and time changes of electric permittivity for $NaNbO_3$ ceramic has been observed. Results of this investigations ...