Dielectric constants of yttrium and rare-earth garnets:

The polarizability of gallium oxide and the oxide additivity rule.

R .D. Shannon, M.A. Subramanian

Central Researach and Development Department
E.I. Du Pont de Nemours and Co., Experimental Station
Wilmington, Delzaware 19880-0356, USA

T. H. Allik

Science Applicatins International Corporation
1710 Goodridge Drive, P.O. Box 1303
McLean, Virginia 22102

H. Kimura

National Research Institute for Metals
1-2-1 Sengen, Tsukuba, Ibaraki 305, Japan

M.R. Kokta

Union Carbide Corp.
750 So. 32nd Street, P.O. Box 6381
Washougal, Washington 98671, USA

M.H. Randles

Litton Airtron
P.O. Box 410168, Charlotte, North Carolina 28421-0168, USA

G.R. Rossman

Dividion of Geological and Planetary Sciences
California Institute of Technology
Pasadena, California, 91125-2500, USA

 

Abstract

The dielectric constants () and dielectric loss values of 10 rare-earth gallium garnets and 1 rare-earth aluminum garnet were measured at 1 MHz using a two-terminal method with empirically determined edge corrections. The results are:

Compound   Compound
(Dy3A15O12) 11.07 ± 0.05   (Ho3Ga5O12) 12.38 ± 0.05
(Dy3Ga5O12) 12.36 ± 0.06   (Th3Ga5O12) 12.40 ± 0.03
(Gd3Ga5O12) 12.18 ± 0.10   (Eu3Ga5O12) 12.46 ± 0.05
(Sm3Ga5O12) 12.55 ± 0.03   (Nd3Ga5O12) 12.59 ± 0.12
(Y3Sc2Ga3O12) 12.94 ± 0.03   (Sm3Sc2Ga3O12) 13.67 ± 0.04
(La2.67Lu2.67Ga2.66O12) 14.40 ± 0.03      

The dielectric polarizability of Ga2O3 derived from the dielectric constants of these and other Ga compounds is 8.80 ± 0.14 Å3. The agreement between measured dielectric polarizabilities as determined from the Clausius-Mosotti equation and those calculated from the sum of oxide polarizabilities according to aD(mineral) = åaD(oxides) for six aluminum garnets and twelve gallium garnets is ~1%.


Journal of Applied Physics 67, 3798-3802. (1990)