Effect of Frequency Variation on the Dielectric Permittivity of an Epoxy-Anhydride Resin System Containing Various Metal Acetylacetonate Accelerators

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

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Dielectric permittivity in the x-ray region

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.0126.197811d.0479 ◽

1978 ◽

Vol 126 (11) ◽

pp. 479-513 ◽

Cited By ~ 8

Author(s):

A.V. Kolpakov ◽

V.A. Bushuev ◽

R.N. Kuz'min

Keyword(s):

Dielectric Permittivity ◽

X Ray

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Dielectric Permittivity of Heterogeneous Disperse Systems

Telecommunications and Radio Engineering ◽

10.1615/telecomradeng.v53.i7-8.330 ◽

1999 ◽

Vol 53 (7-8) ◽

pp. 200-203 ◽

Cited By ~ 3

Author(s):

S. V. Gatash ◽

L. D. Styopin

Keyword(s):

Dielectric Permittivity ◽

Disperse Systems

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The Determination of the Magnetoelectric Coupling Coefficient in Ferroelectric–Ferromagnetic Composite Based on PZT–Ferrite

Archives of Metallurgy and Materials ◽

10.2478/amm-2013-0183 ◽

2013 ◽

Vol 58 (4) ◽

pp. 1401-1403 ◽

Cited By ~ 3

Author(s):

J.A. Bartkowska ◽

R. Zachariasz ◽

D. Bochenek ◽

J. Ilczuk

Keyword(s):

Dielectric Permittivity ◽

Coupling Coefficient ◽

Mean Field ◽

Field Approximation ◽

Theoretical Description ◽

Magnetoelectric Coupling ◽

Mean Field Approximation ◽

Dielectric Measurements ◽

Temperature Dependences ◽

Multiferroic Composite

Abstract In the present work, the magnetoelectric coupling coefficient, from the temperature dependences of the dielectric permittivity for the multiferroic composite was determined. The research material was ferroelectric-ferromagnetic composite on the based PZT and ferrite. We investigated the temperature dependences of the dielectric permittivity (") for the different frequency of measurement’s field. From the dielectric measurements we determined the temperature of phase transition from ferroelectric to paraelectric phase. For the theoretical description of the temperature dependence of the dielectric constant, the Hamiltonian of Alcantara, Gehring and Janssen was used. To investigate the dielectric properties of the multiferroic composite this Hamiltonian was expressed under the mean-field approximation. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified.

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