ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The effects of Bi-substitution on the complex impedance spectra of yttrium iron garnet (YIG)were studied in this paper. The polycrystalline yttrium iron garnet Y2BiFe5O12 (YIG: Bi) and Y3Fe5O12(YIG) samples were prepared by solid-reaction method. The complex impedance spectra were measuredin the frequency range from 1 KHz to 100MHz at several temperatures between 210oC and 500oC. Thecomplex impedance sample shows that the YIG: Bi can be represented by double Cole-Cole semicircles,and the YIG can be represented by a single Cole semicircle. The physical structure of the specimen wasvisualized as comprising of small resistance grains separated by large resistance grain boundaries inaccordance with the impedance spectra observations. The electrical processes in the sample weremodeled in the form of an electrical equivalent circuit made up of a series combination of two parallel RCcircuits attributed to grains and grain boundaries. The temperature dependence of bulk resistanceindicated an evidence of Arrhenius-type thermally activated process, showing a close to linear variationup to a temperature of 740 K
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.336-338.709.pdf
