Effect of H2O on dielectric properties of berlinite. I. Dielectric constant

Autor: M C Wintersgill, B. H. T. Chai, J J Fontanella, R D Shannon
Rok vydání: 1993
Předmět:
Zdroj: Journal of Physics D: Applied Physics. 26:93-100
ISSN: 1361-6463
0022-3727
DOI: 10.1088/0022-3727/26/1/015
Popis: The dielectric constants of a series of hydrothermally grown berlinite crystals containing increasing amounts of H2O were determined using a two-terminal method and empirically determined edge corrections with kappa 11T ranging from 4.67 to 4.86 and kappa 33T from 4.54 to 4.76. The extrapolated values for 'dry' berlinite are kappa 11S= kappa 33S=4.55. Infrared studies of these crystals show bands at 4400 and 5200 cm-1 which are attributed respectively to hydroxyl ions and macroscopic and microscopic inclusions of the 6-7 M HCl/H3PO4 growth medium. The hydroxyl ions are believed to result from terminal P-OH groups at the surfaces of inclusions or as (4H)Al or (3H)Al hydroxyl nests. The OH- groups have a negligible influence on the dielectric constant, whereas the inclusions are responsible for the increase in kappa aaS and kappa 33T to 4.8 over the dry value of 4.55.
Databáze: OpenAIRE