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Temperature Stability in Yttrium‐Gadolinium‐Aluminum‐Iron Garnets
Author(s) -
HODGES L. R.,
HARRISON GORDON R.
Publication year - 1965
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1965.tb14652.x
Subject(s) - curie temperature , yttrium , gadolinium , materials science , magnetization , yttrium iron garnet , atmospheric temperature range , nuclear magnetic resonance , analytical chemistry (journal) , condensed matter physics , chemistry , metallurgy , ferromagnetism , thermodynamics , oxide , magnetic field , physics , chromatography , quantum mechanics
The gadolinium‐substituted yttrium‐iron garnets have a compensation point of the magnetization (a temperature below the Curie point where the magnetization goes rapidly to zero). The temperature at which this compensation point occurs is determined primarily by the gadolinium content but may be further repositioned by the substitution of aluminum for iron. By proper control of these compensation points by ionic substitutions, microwave garnet materials may be produced having magnetizations which are temperature independent. The microwave properties of the following compositions were investigated:for x = 0 to 0.5 and w = 0 to 0.3. The magnetizations of these materials were studied from—195°C to the Curie temperature. This series of substitutions resulted in materials with magnetizations of 800 to 300 gauss, which vary no more than ±50 gauss over a 120°C temperature range encompassing—40° to +40°C. The line‐width of these temperature‐stable materials is less than 120 oe at room temperature. These materials are useful in many temperature‐stable microwave components including low‐frequency circulators.