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US4092208A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of growing single crystals of rare earth metal iron garnet materials

Assignee: US Philips Corp
•
Filing: 1977-05-06
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Granted: 1978-05-30
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Expires: 1997-05-06
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Abstract

Abstract A method of growing monocrystalline bismuth rare earth iron garnet, either as a single crystal or as an epitaxial layer, from a solution containing composing components of the garnet together with a flux. The flux consists essentially of a mixture of Bi 2 O 3 and RO 2 , wherein R is at least one of the elements Si, Ge, Ti, Sn, Zr, Ce and Te, wherein the system Bi 2 O 3 --RO 2 includes a eutectic composition having a eutectic temperature which is below the melting temperature of pure Bi 2 O 3 . By using these Bi 2 O 3 --RO 2 fluxes, the monocrystalline garnets produced have lower optical absorption coefficients at, for example 5100 A and 5600 A than similar garnets grown using lead-containing fluxes. Furthermore higher growth rates and higher growth temperatures are possible when using the Bi 2 O 3 --RO 2 fluxes rather than lead-containing fluxes.

Inventors

  • 👤 John Chadwick Brice
  • 👤 John Mackay Robertson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 20:02
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; H01F41/24; H01F41/28; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2675; C30; C30B; C30B19/00; C30B19/02; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/28; C30B9/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 134 words
In the method of growing a monocrystalline bismuth rare earth iron garnet from a melt consisting of a solution containing the constituents of the garnet by crystallization from said melt, the improvement wherein the solution in addition to said constituents contains a flux consisting essentially of a mixture of Bi 2 O 3 and RO 2 wherein R is at least one element selected from the group consisting of Si, Ge, Ti, Sn, Zr, Ce and Te the proportion of Bi 2 O 3 and RO 2 being such as to form a eutectic composition the eutectic temperature of which is below the melting temperature of pure Bi 2 O 3 and the proportion of Bi 2 O 3 in the solution being in excess of that required as a constituent of the garnet.
Claim 2
Dependent Claim 134 words
In the method of growing a monocrystalline bismuth rare earth iron garnet from a melt consisting of a solution containing the constituents of the garnet by crystallization from said melt, the improvement wherein the solution in addition to said constituents contains a flux consisting essentially of a mixture of Bi 2 O 3 and RO 2 wherein R is at least one element selected from the group consisting of Si, Ge, Ti, Sn, Zr, Ce and Te the proportion of Bi 2 O 3 and RO 2 being such as to form a eutectic composition the eutectic temperature of which is below the melting temperature of pure Bi 2 O 3 and the proportion of Bi 2 O 3 in the solution being in excess of that required as a constituent of the garnet.
Claim 3
Dependent Claim 30 words
A method of claim 1, wherein a monocrystalline bismuth rare earth iron garnet epitaxial layer is grown by crystallization from the melt on a crystal face of a monocrystalline substrate.
Claim 4
Dependent Claim 17 words
A method as claimed in claim 1, wherein the growth temperature is between 720° and 900° C.
Claim 5
Dependent Claim 24 words
A method as claimed in claim 3, wherein the viscosity of the flux mixture at the growth temperature is not more than 16 centipoises.
Claim 6
Dependent Claim 27 words
The method of claim 4 wherein a monocrystalline epitaxial layer of a bismuth rare earth iron garnet is grown on a crystal face of a mono-crystalline substrate.

References Cited (Backward Citations)

US3697320A Cited
US3790405A Cited
US3947372A Cited
US3915661A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-05-29 1981-11-28 1982-05-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-05-29 1985-11-28 1986-05-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-05-29 1989-11-28 1990-05-30 $7700.00 Window Closed / Lapsed

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