Complex Impedance Spectroscopy of Bi-Substituted Yttrium Iron Garnet (YIG)

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 measured in the frequency range from 1 KHz to 100MHz at several temperatures between 210oC and 500oC. The complex 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 was visualized as comprising of small resistance grains separated by large resistance grain boundaries in accordance with the impedance spectra observations. The electrical processes in the sample were modeled in the form of an electrical equivalent circuit made up of a series combination of two parallel RC circuits attributed to grains and grain boundaries. The temperature dependence of bulk resistance indicated an evidence of Arrhenius-type thermally activated process, showing a close to linear variation up to a temperature of 740 K.

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Complex Impedance Spectroscopy of Bi-Substituted Yttrium Iron Garnet (YIG)

Key Engineering Materials - High-Performance Ceramics IV ◽

10.4028/0-87849-410-3.709 ◽

2007 ◽

pp. 709-711

Author(s):

Hong Jie Zhao ◽

Ji Zhou ◽

Zhi Lun Gui ◽

Long Tu Li

Keyword(s):

Impedance Spectroscopy ◽

Yttrium Iron Garnet ◽

Complex Impedance ◽

Complex Impedance Spectroscopy ◽

Yttrium Iron ◽

Iron Garnet

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Sub-grain boundaries and dissociations of dislocations in yttrium iron garnet deformed at high temperatures

Philosophical Magazine A ◽

10.1080/01418617908239300 ◽

1979 ◽

Vol 39 (6) ◽

pp. 693-708 ◽

Cited By ~ 27

Author(s):

J. Rabier ◽

P. Veyssiere ◽

H. Garem ◽

J. Grilhé

Keyword(s):

Grain Boundaries ◽

High Temperatures ◽

Yttrium Iron Garnet ◽

Yttrium Iron ◽

Iron Garnet

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Analysis and lattice imaging of a transitional event on garnets

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108490 ◽

1978 ◽

Vol 36 (1) ◽

pp. 270-271

Author(s):

J.Y. Laval

Keyword(s):

Yttrium Iron Garnet ◽

Reciprocal Lattice ◽

Transitional Zone ◽

Lattice Imaging ◽

Yttrium Iron ◽

X Ray ◽

Ionic Process ◽

The Matrix ◽

High Resolution Technique ◽

Iron Garnet

The exsolution of magnetite from a substituted Yttrium Iron Garnet, containing an iron excess may lead to a transitional event. This event is characterized hy the formation of a transitional zone at the center of which the magnetite nucleates (Fig.1). Since there is a contrast between the matrix and these zones and since selected area diffraction does not show any difference between those zones and the matrix in the reciprocal lattice, it is of interest to analyze the structure of the transitional zones.By using simultaneously different techniques in electron microscopy, (oscillating crystal method microdiffraction and X-ray microanalysis)one may resolve the ionic process corresponding to the transitional event and image this event subsequently by high resolution technique.

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