Dielectric Constants of YVO4, Fe-, Ge-, and V-Containing Garnets, the POlarizabilities of Fe2O3, GeO2, and V2O5, and the Oxide Additivity Rule

R.D. Shannon, R.A. Oswald
E. I. Du Pont de Nemours and Co., Inc., Central Research and Development Department,
Experimental Station, Wilmington, DE 19880-0356, U.S.A.

T.H. Allik
Science Applications Internatinoal Corporation, 1710 Goodridge Dr.
P.O. Box 1303, McLean, VA  22102

J.P.M. Damen
Phillips Research Laboratories
Eindhoven, The Netherlands

D. Mateika
Philips GmbH Forschungslaboratorium Hamburg
Vogt-Kolln-Strasse 30
D-2000 Hamburg 54, Federal Republic of Germany

B.A. Wechsler
Hughes Research Laboratories
3011 Malibu Canyon Rd.
Malibu, CA 90265

G.R. Rossman
Division of Geological and Planetary Sciences
California Institute of Technology, Pasadena, CA 91125-2500, U.S.A

Abstract

The dielectric constants and dissipation facctors of Y3Fe5O12, YVO4, NaCa2Mg2V3O12 and a variety of Ge garnets were determined at 1 MHz using a two-terminal method and empiriclly determined edge corrections. The results are:

Y3Fe5O12

 κ' = 8.79 tan δ = 0.0009
Ca3Ga2Ge3O12

 κ' = 10.20 tan δ = 0.0007
Ca.90Y1.88Mg2.27Ge3O12

 κ' = 10.35 tan δ = 0.0006
CaY1.96Nd.04Zn2Ge3O12

 κ' = 11.32 tan δa = 0.0006
Nd2.95Mg1.48In.68Ga1.54Ge1.32O12

 κ' = 11.86 tan δ = 0.0009
Na3Ca2Mg2V2O12

 κ' = 10.32 tan δ = 0.0010
YVO4

 κ'a = 9.68
κ'c = 16.59		 tan δa = 0.0010
tan δc = 0.0278

The dielectric polarizabilities of Fe2O3, GeO2, and V2O3 derived from the dielectric constants of the above compounds are 10.5, 5.5, and 15.8 Å3, respectively. 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) =  ΣaD(oxides) for the above garnets is ~0.5%.


J Solid State Chemistry (1991) 95:313-318.