Effect Of H2O On Dielectric-Properties Of Berlinite .2. Dielectric Loss

    Authors

    J. J. Fontanella; M. C. Wintersgill; R. D. Shannon;B. H. T. Chai

    Comments

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    Abbreviated Journal Title

    J. Phys. D-Appl. Phys.

    Keywords

    Alpha-Quartz; Relaxation; Pressure; Aluminum; Physics, Applied

    Abstract

    Audio frequency complex Impedance measurements have been carried out over the temperature range 5.5-38 K on samples of berlinite (aluminium phosphate) both parallel and perpendicular to the optic axis. The berlinite samples contain varying amounts of water. All of the berlinite samples exhibit a dielectric relaxation peak in the vicinity of 40 K and 1000 Hz. The data were best fit using an expression based on the stretched exponential (SE). The best fit SE parameter betaSE ranges from 0.68 to 0.85. In the direction perpendicular to the optic axis, the activation energy is approximately 0.053 eV and the relaxation is correlated with the aqueous solution inside inclusions. The relaxation parallel to the optic axis has an activation energy of about 0.049 eV and is attributed to hydroxyl ions at the surface of the inclusions. A dielectric relaxation peak is also observed near 240 K and 1000 Hz for the samples with a higher nominal water concentration. In addition, dielectric loss, which is attributed to trace impurities or Maxwell-Wagner polarization of inclusions, is observed in the vicinity of room temperature.

    Journal Title

    Journal of Physics D-Applied Physics

    Volume

    26

    Issue/Number

    1

    Publication Date

    1-1-1993

    Document Type

    Article

    Language

    English

    First Page

    101

    Last Page

    105

    WOS Identifier

    WOS:A1993KH16700016

    ISSN

    0022-3727

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