Search results for "Dissipation factor"
showing 6 items of 6 documents
Electric and dielectric properties of nanostructured stoichiometric and excess-iron Ni–Zn ferrites
2013
In this paper, we report a study of the effect of excess iron on structural, microstructural, electric and dielectric properties of the nanostructured Ni–Zn ferrites Ni1−xZnxFe2+zO4−δ of different compositions with x = 0, 0.3, 0.5, 0.7, 1 and z = 0, 0.1. The structural and microstructural properties are estimated from x-ray diffraction and atomic force microscopy (AFM) data. The average grain size, evaluated from AFM topographical analysis, is found to be below 70 nm. The samples exhibit low values of dielectric constant and dielectric loss and a high resistivity. Contrary to earlier conclusions regarding microstructured Ni–Zn ferrites, in nanostructured Ni–Zn ferrites sintered at relativel…
Relaxor ferroelectric PbSc1/2Nb1/2O3—PbZn1/3Nb2/3O3— PbMg1/3Nb2/3O3ceramics
2000
Abstract Original ternary solid solutions PbSc1/2Nb1/2O3 — PbZn1/3Nb2/3O3-PbMg1/3Nb2/3O3 (PSN-PZN-PMN) have been synthesized by solid state reaction from oxides. Ceramic samples have been obtained by both conventional and hot pressing techniques. The density of the obtained hot pressed ceramics reaches 98% of the value calculated from X-ray data. Dense, high quality samples of pure PZN and compositions containing over 0.8 molar parts of PZN could not be obtained — porosity was up to 10% and they were mainly comprised of the cubic pyrochlore phase. Density, porosity, water absorbtivity, and dielectric permittivity and dissipation factor of the ceramic samples have been measured. Data of diff…
Transformation Algorithm of Dielectric Response in Time-Frequency Domain
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/547105 A transformation algorithm of dielectric response from time domain to frequency domain is presented. In order to shorten measuring time of low or ultralow frequency dielectric response characteristics, the transformation algorithm is used in this paper to transform the time domain relaxation current to frequency domain current for calculating the low frequency dielectric dissipation factor. In addition, it is shown from comparing the calculation results with actual test data that there is a coincidence for both results over a wide …
Dielectric properties of barium strontium titanate / non ferroelectric oxide ceramic composites
2001
International audience; Barium strontium titanate ceramics present high dielectric permittivity and tunability. In order to reduce their permettivity and loss tangent while keeping tunability, various composites of barium strontium titanate oxide...
BST ceramics: Effect of attrition milling on dielectric properties
2004
Abstract The effect of grain size on the dielectric properties of Ba0.6Sr0.4TiO3 (BST) ceramics is investigated. Attrition milling is chosen to obtain nanometre particle size from micrometre particle size powders. Fine grained ceramics are obtained by hot uniaxial pressing (HUP). Additionally, the present study is focused on the effect of the nature of milling balls on loss tangent and permittivity. For that, three kinds of balls are tested: calcia, yttria or ceria stabilised zirconia balls. The properties of these samples are evaluated in the range of MHz. The balls induce an involuntary doping of powders which modifies the dielectric properties, especially the Curie temperature and loss t…
Dynamic mechanical properties of semi-interpenetrating networks based on poly(styrene-co-maleic anhydride)
1991
Semi-interpenetrating networks based on linear anionic polystyrene (PS) and poly(styrene-co-maleic anhydride) P(ScoMA) of low MA content are prepared by crosslinking the P(ScoMA) with 4,4′-diphenylmethanediamine (DPMDA). It is demonstrated by dynamic mechanical analysis and by DSC that immiscible semi-IPN's are obtained for MA contents greater 5 wt.-%. In miscible semi-IPN's the relaxation of free PS chains is observed as a second maximum in the loss tangent at higher temperatures. The position of this maximum is shifted to higher temperatures for a polystyrene of molecular weight 500000 compared to a polystyrene of molecular weight 150000. The experimental temperature shift is in good agre…