Yttrium iron garnet
| Yttrium iron garnet | |
|---|---|
 |
|
| General and classification | |
| chemical formula | Y 3 Fe 2 (FeO 4 ) 3 or Y 3 Fe 5 O 12 |
|
Mineral class (and possibly department) |
Garnet group |
| Crystallographic Data | |
| Crystal system | cubic |
| Crystal class ; symbol | cubic-hexakisoctahedral 4 / m 3 2 / m |
| Frequent crystal faces | {110}, subordinate to {100}, {111} depending on the manufacturing conditions |
| Physical Properties | |
| Mohs hardness | 6.5 to 7 |
| Density (g / cm 3 ) | 5.17 |
| Cleavage | Please complete |
| colour | dark red to black |
| Line color | red |
| transparency | not visible |
| shine | dark metallic |
| radioactivity | not radioactive |
| magnetism | ferrimagnetic |
| Crystal optics | |
| Refractive index | n = 2.2 at 1.31 µm |
| Birefringence | no |
Yttrium iron garnet, short YIG ( engl. Yttrium Iron Garnet), is an artificially made garnet of the composition Y 3 Fe 2 (Fe O 4 ) 3 or Y 3 Fe 5 O 12 . The CAS number is 12063-56-8. This garnet has not yet been found in nature. YIG is a ferrimagnetic insulator, the Curie temperature is 550 K.
YIG shows a strong Faraday effect , has a high quality in the microwave range and a very small line width in the electron spin resonance. The material is therefore used in microwave, optical and magneto-optical applications, e.g. B. as a frequency-determining element in the resonator of YIG oscillators and in YIG filters for frequencies in the gigahertz range.
Single crystals can be produced by various methods. For example, chemical transport reactions and gas phase separations with chlorides for the production of single crystals a few millimeters in size are described in the literature . Manufacture using the crucible-free zone melting process and even the Verneuil process is also described. Optically high-quality single crystals with a diameter of about 5 cm were also obtained from the melt solution.
See also
literature
- J. Helszajn: YIG Resonators and Filters. John Wiley & Sons, New York 1985.
- K.-Th. Wilke, J. Bohm: Kristallzüchtung, VEB Deutscher Verlag der Wissenschaften, Berlin 1988, ISBN 3-326-00092-8
- isowave.com: Yttrium Iron Garnet ( Memento from February 20, 2012 in the Internet Archive ) (table with selected material parameters )