US3788896A - Method for producing bubble domains in magnetic film-substrate structures - Google Patents
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- US3788896A US3788896A US00101787A US3788896DA US3788896A US 3788896 A US3788896 A US 3788896A US 00101787 A US00101787 A US 00101787A US 3788896D A US3788896D A US 3788896DA US 3788896 A US3788896 A US 3788896A
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- 239000000758 substrate Substances 0.000 title abstract description 43
- 238000004519 manufacturing process Methods 0.000 title abstract description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 49
- 239000002223 garnet Substances 0.000 abstract description 26
- 229910052742 iron Inorganic materials 0.000 abstract description 25
- 238000000034 method Methods 0.000 abstract description 19
- 230000008021 deposition Effects 0.000 abstract description 3
- 239000010408 film Substances 0.000 description 44
- 239000013078 crystal Substances 0.000 description 13
- 239000000463 material Substances 0.000 description 13
- 238000000151 deposition Methods 0.000 description 10
- 239000000470 constituent Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 238000009472 formulation Methods 0.000 description 6
- 230000005415 magnetization Effects 0.000 description 6
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 5
- 229910052772 Samarium Inorganic materials 0.000 description 5
- 229910052733 gallium Inorganic materials 0.000 description 5
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 229910052727 yttrium Inorganic materials 0.000 description 3
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 3
- 229910052684 Cerium Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 229910052691 Erbium Inorganic materials 0.000 description 2
- 229910052693 Europium Inorganic materials 0.000 description 2
- 229910052688 Gadolinium Inorganic materials 0.000 description 2
- 229910052689 Holmium Inorganic materials 0.000 description 2
- 229910052765 Lutetium Inorganic materials 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 229910052773 Promethium Inorganic materials 0.000 description 2
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 229910052775 Thulium Inorganic materials 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910052769 Ytterbium Inorganic materials 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 2
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 2
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 2
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 2
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- OHSVLFRHMCKCQY-UHFFFAOYSA-N lutetium atom Chemical compound [Lu] OHSVLFRHMCKCQY-UHFFFAOYSA-N 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 2
- VQMWBBYLQSCNPO-UHFFFAOYSA-N promethium atom Chemical compound [Pm] VQMWBBYLQSCNPO-UHFFFAOYSA-N 0.000 description 2
- 229910052706 scandium Inorganic materials 0.000 description 2
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 2
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 2
- NAWDYIZEMPQZHO-UHFFFAOYSA-N ytterbium Chemical compound [Yb] NAWDYIZEMPQZHO-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- JNDMLEXHDPKVFC-UHFFFAOYSA-N aluminum;oxygen(2-);yttrium(3+) Chemical compound [O-2].[O-2].[O-2].[Al+3].[Y+3] JNDMLEXHDPKVFC-UHFFFAOYSA-N 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 244000309464 bull Species 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- ZSOJHTHUCUGDHS-UHFFFAOYSA-N gadolinium iron Chemical compound [Fe].[Gd] ZSOJHTHUCUGDHS-UHFFFAOYSA-N 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- UCNNJGDEJXIUCC-UHFFFAOYSA-L hydroxy(oxo)iron;iron Chemical compound [Fe].O[Fe]=O.O[Fe]=O UCNNJGDEJXIUCC-UHFFFAOYSA-L 0.000 description 1
- -1 iron ions Chemical class 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910019901 yttrium aluminum garnet Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
- H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
- H01F10/18—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being compounds
- H01F10/20—Ferrites
- H01F10/24—Garnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
- H01F41/24—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates from liquids
- H01F41/28—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates from liquids by liquid phase epitaxy
Definitions
- a method for producing a bubble domain in a magnetic single crystal garnet film-substrate structure involves the epitaxial deposition of an iron garnet film of the proper orientation and having a negative magnetostriction constant on a garnet substrate in which the room temperature lattice constant of the film is larger than the room temperature lattice con stant of the substrate by an amount greater than about 0.035 angstrom.
- This invention relates to bubble domains and more particularly to a method of forming a film having bubble domains therein.
- Some iron garnet film-substrate structures were observed to have domains whose magnetization directions are in the plane of the film in. contrast to the desired bubble domains whose magnetization directions are perpendicular to the plane of the film.
- a specific step in the method involves depositing a single crystal iron garnet film of the proper crystallographic orientation and having a negative magnetostriction constant on a substrate in which the room temperaturelattice constant of the film is larger than the room temperature lattice con- 3,788,896 Patented Jan. 29, 1974 apparent from the following detailed description wherein a preferred embodiment of the present invention is clearly shown.
- the drawing shows a magnetic bubble domain filmsubstrate structure made in accordance with the method of this invention.
- This invention involves a process in which a single crystal iron garnet material is chemically vapor deposited to form a film on a substrate. It is necessary that the single crystal material have the proper crystallographic orientation to take advantage of the negative magnetostriction.
- the room lattice constant of the deposited film is larger than the room lattice constant of the substrate by an amount greater than about 0.035 angstrom.
- the resultant film-substrate structure has a craze-free film with bubble domains therein.
- the normal source of uniaxial anisotropy observed in magnetic material is the crystal structure of the material.
- a A 0 negative magnetostriction constants
- o' 0 easy axis of magnetization if the platelet is in tension
- o' 0 hard axis if the platelet is in compression
- 0' is the stress in the plane of the material.
- the room temperature magnetostriction constants of selected iron garnets are listed in the following table.
- Magnetostriction constant Iron garnet Moo X10 Mn
- the values of the magnetostriction constants of the iron garnet material, as well as its magnetization, can be varied by depositing a film containing a mixture of two or more pure iron garnets and/ or by substituting other cations for iron ions.
- the dominant source of uniaxial anisotropy is the magnetostrictive efiect resulting from the stress existing in the film. This stress is due to the difference between the lattice constants and the thermal expansion coefiicients of the film and substrate and may be in the form of tension or compression.
- This invention specifically covers a method of forming a bubble domain structure by depositing a magnetic single crystal garnet film of the proper orientation and having a negative magnetostriction constant on a substrate in which the film is in tension.
- an oxide substrate is preferably subjected to a chemical vapor deposition step to provide a thin film of magnetic bubble domain material, film 12.
- the deposition step is carried out in accordance with the co-pending application, Ser. No. 833,268 filed June 16, 1969 and now abandoned, and assigned to the assignee of the present invention. This pending patent application is incorporated herewith by reference hereto.
- the Q constituent of the film formulation is taken from the group consisting of iron, iron and aluminum, iron and gallium, iron and indium, iron and scandium, iron and titalium, iron and vanadium, iron and chromium, and iron and manganese.
- a preferred substrate material is samarium gallium garnet when the film material is gadolinium iron garnet.
- an iron garnet film of the proper orientation and having a negative magnetostriction constant is deposited on a garnet substrate in which the room temperature lattice constant of the film is larger than the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom.
- the film lattice constant exceeds the substrate lattice constant by an amount greater than about 0.035 angstrom the film is in tension and bubble domains are present therein.
- the film lattice constant is larger than the substrate lattice constant by an amount less than about 0.035 angstrom, the film is in compression and there are no bubble domains since the normal to plane of the film is the hard axis and the domain magnetizations lie in the plane.
- the difference in the coefficients of thermal expansion between the fihn and the substrate contributes to total stress present in the film.
- the thermal expansion stress contribution is within acceptable limits as long as the coefiicient of thermal expansion of the substrate is the same as or lower than that of the film by an amount not more than 1X10-/ C.
- a certain amount of mismatch between film-substrate room temperature lattice constants and/or thermal expansion characteristics is required in order to provide the stress which produces the uniaxial anisotropy necessary for bubble domain formation. It film and substrate are too closely matched in both lattice constant and thermal expansion, the proper stress necessary for bubble domain formation will not be achieved.
- the substrate 10 is monocrystalline garnet having a I Q O formulation wherein the J constituent of the wafer formulation is at least one element selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, lanthanum, yttrium, calcium, and bismuth and the Q constituent of the wafer formulation is at least one element selected from the group consisting of indium, gallium, scandium, titanium, vanadium, chromium, manganese, rhodium, zirconium, hafnium, molybdenum, tungsten, niobium, tantalum, aluminum, phosphorus, arsenic and antimony.
- the J constituent of the wafer formulation is at least one element selected from the group consisting of cerium, praseodymium
- substrate materials are samarium gallium garnet, and yttrium aluminum garnet.
- the film of the bubble domain material is a single crystal garnet film having a J Q 0 formulation wherein the J constituent of the film formulation has at least one element selected from the group of cerium, praseodymium,
- a method of producing a bubble domain containing film-substrate structure comprising the step of depositing a magnetic film of a single crystal material of the proper orientation and having a negative magnetostriction constant on a substrate in which the magnetic film has a room temperature lattice constant which exceeds the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom.
- a method of producing a bubble domain containing film-substrate structure comprising the step of depositing an iron garnet film of the proper orientation and having a negative magnetostriction constant on a substrate in which the iron garnet film has a room temperature lattice constant which exceeds the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom.
- a method of producing a bubble domain containing film-substrate structure comprising the step of depositing angstrom.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
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- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Thin Magnetic Films (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
A METHOD FOR PRODUCING A BUBBLE DOMAIN IN AMAGNETIC SINGLE CRYSTLA GARNET FILM-SUBSTRATE STRUCTURE IS DISCLOSED. THE METHOD INVOLVES THE EPTIAXIAL DEPOSITION OF AN IRON GARNET FILM OF THE PROPER ORIENTATION AND HAVING A NEGATIVE MAGNETOSTRICTION CONSTANT ON A GARNET SUBSTRATE IN WHICH THE ROOM TEMPERATURE LATTICE CONTHE FILM IS LARGER THAN THE ROOM TEMPERATURE LATTICE CONSTANT OF THE SUBSTRATE BY AN AMOUNT GREATER THAN ABOUT 0.035 ANGATROM.
D R A W I N G
D R A W I N G
Description
Jan. 29, 1974 J. E. MEE ETAL INVENTORS JACK E. MEE BY PAUL J. BESSER ATTORNEY United States Patent 3,788,896 METHOD FOR PRODUCING BUBBLE DOMAINS IN MAGNETIC FILM-SUBSTRATE STRUCTURES Jack E. Mee, Anaheim, and Paul J. Besser, Mission Viejo,
Califi, assignors to North American Rockwell Corporation, El Segundo, Calif.
Filed Dec. 28, 1970, Ser. No. 101,787 Int. Cl. H01f 10/06 U.S. Cl. 117-235 5 Claims ABSTRACT OF THE DISCLOSURE A method for producing a bubble domain in a magnetic single crystal garnet film-substrate structure is disclosed. The method involves the epitaxial deposition of an iron garnet film of the proper orientation and having a negative magnetostriction constant on a garnet substrate in which the room temperature lattice constant of the film is larger than the room temperature lattice con stant of the substrate by an amount greater than about 0.035 angstrom.
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to bubble domains and more particularly to a method of forming a film having bubble domains therein.
(2) Description of prior art Magnetic bubble domains in a sheet of magnetic medium, such as yttrium orthoferrite, are well known in the art and are described in U.S. Pat. No. 3,460,116 and others. Magnetic bubble domains in composite structures having a thin film of a single crystal iron garnet on an oxide substrate are disclosed in the co-pending patent applications to Mee et al., U.S. Ser. Nos. 16,446 filed Mar. 4, 1970 and now U.S. Pat. No. 3,645,788, and 16,447, filed Mar. 4, 1970. These co-pending patent applications are incorporated herewith.
Some iron garnet film-substrate structures were observed to have domains whose magnetization directions are in the plane of the film in. contrast to the desired bubble domains whose magnetization directions are perpendicular to the plane of the film.
SUMMARY OF THE INVENTION It is a primary object of this invention to provide an improved method of forming a single crystal iron garnet film-substrate structure having bubble domains therein.
This and other objects of this invention are accomplished by a method in which the uniaxial anisotropy necessary for bubble domain formation in film-substrate structure is affected by proper control of the mechanical stress present in the film at room temperature. A specific step in the method involves depositing a single crystal iron garnet film of the proper crystallographic orientation and having a negative magnetostriction constant on a substrate in which the room temperaturelattice constant of the film is larger than the room temperature lattice con- 3,788,896 Patented Jan. 29, 1974 apparent from the following detailed description wherein a preferred embodiment of the present invention is clearly shown.
BRIEF DESCRIPTION OF THE DRAWING The drawing shows a magnetic bubble domain filmsubstrate structure made in accordance with the method of this invention.
DETAILED DESCRIPTION OF THE INVENTION This invention involves a process in which a single crystal iron garnet material is chemically vapor deposited to form a film on a substrate. It is necessary that the single crystal material have the proper crystallographic orientation to take advantage of the negative magnetostriction. In addition the room lattice constant of the deposited film is larger than the room lattice constant of the substrate by an amount greater than about 0.035 angstrom. The resultant film-substrate structure has a craze-free film with bubble domains therein.
In general, the normal source of uniaxial anisotropy observed in magnetic material is the crystal structure of the material. When single crystal platelets with negative magnetostriction constants (A A 0), are under stress the magnetostriction contribution tends to make the normal to the plane of the platelet an easy axis of magnetization if the platelet is in tension, (o' 0), and a hard axis if the platelet is in compression, (o' 0) where A and M are the saturation valves of the linear magnetostriction constants along the 100 and 111 directions, respectively, and 0' is the stress in the plane of the material.
The room temperature magnetostriction constants of selected iron garnets are listed in the following table.
Magnetostriction constant Iron garnet Moo (X10 Mn (X The values of the magnetostriction constants of the iron garnet material, as well as its magnetization, can be varied by depositing a film containing a mixture of two or more pure iron garnets and/ or by substituting other cations for iron ions.
It is understood that whether there is mixing and/or substitution or not, the condition for bubble domain formation in the iron garnet material, H /41rM 1, has to be satisfied, where H is the uniaxial anisotropy field and 41rM is the magnetization.
In magnetic oxide film-substrate structures formed by chemical vapor deposition, the dominant source of uniaxial anisotropy is the magnetostrictive efiect resulting from the stress existing in the film. This stress is due to the difference between the lattice constants and the thermal expansion coefiicients of the film and substrate and may be in the form of tension or compression.
This invention specifically covers a method of forming a bubble domain structure by depositing a magnetic single crystal garnet film of the proper orientation and having a negative magnetostriction constant on a substrate in which the film is in tension.
A co-pending application to Mee et al., Ser. No. 101,785 filed Dec. 28, 1970, covers a method of forming a bubble domain structure by depositing a magnetic single crystal garnet film of the proper orientation and having a positive magnetostriction constant on a substrate in which the film is in compression.
A co-pending application to Mee et al., Ser. No. 101,786 filed Dec. 28, 1970, covers a second method of forming a bubble domain structure by depositing a magnetic single crystal garnet film of the proper orientation and having a negative magnetostriction constant on a substrate in which the film is in tension.
As shown in the drawing, an oxide substrate is preferably subjected to a chemical vapor deposition step to provide a thin film of magnetic bubble domain material, film 12. The deposition step is carried out in accordance with the co-pending application, Ser. No. 833,268 filed June 16, 1969 and now abandoned, and assigned to the assignee of the present invention. This pending patent application is incorporated herewith by reference hereto.
neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, lanthanum and yttrium; the Q constituent of the film formulation is taken from the group consisting of iron, iron and aluminum, iron and gallium, iron and indium, iron and scandium, iron and titalium, iron and vanadium, iron and chromium, and iron and manganese.
The valence of the I constituent and the valence of the Q constituent add up to the same valence total as the oxide constituent. A preferred substrate material is samarium gallium garnet when the film material is gadolinium iron garnet.
In accordance with this invention, an iron garnet film of the proper orientation and having a negative magnetostriction constant is deposited on a garnet substrate in which the room temperature lattice constant of the film is larger than the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom. When the film lattice constant exceeds the substrate lattice constant by an amount greater than about 0.035 angstrom the film is in tension and bubble domains are present therein. When the film lattice constant is larger than the substrate lattice constant by an amount less than about 0.035 angstrom, the film is in compression and there are no bubble domains since the normal to plane of the film is the hard axis and the domain magnetizations lie in the plane.
As previously discussed, the difference in the coefficients of thermal expansion between the fihn and the substrate contributes to total stress present in the film. The thermal expansion stress contribution is within acceptable limits as long as the coefiicient of thermal expansion of the substrate is the same as or lower than that of the film by an amount not more than 1X10-/ C. A certain amount of mismatch between film-substrate room temperature lattice constants and/or thermal expansion characteristics is required in order to provide the stress which produces the uniaxial anisotropy necessary for bubble domain formation. It film and substrate are too closely matched in both lattice constant and thermal expansion, the proper stress necessary for bubble domain formation will not be achieved.
or by a liquid phase epitaxial process.
The substrate 10 is monocrystalline garnet having a I Q O formulation wherein the J constituent of the wafer formulation is at least one element selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, lanthanum, yttrium, calcium, and bismuth and the Q constituent of the wafer formulation is at least one element selected from the group consisting of indium, gallium, scandium, titanium, vanadium, chromium, manganese, rhodium, zirconium, hafnium, molybdenum, tungsten, niobium, tantalum, aluminum, phosphorus, arsenic and antimony.
Examples of substrate materials are samarium gallium garnet, and yttrium aluminum garnet.
The film of the bubble domain material is a single crystal garnet film having a J Q 0 formulation wherein the J constituent of the film formulation has at least one element selected from the group of cerium, praseodymium,
TABLE Substratm Film Substrate lattice constant Lattice Lattice minus film Orienconstant,- Orienconstant,- lattice Bubble Domains iEx. No. Material tion A. Substrate tation A. constant-,A. domain in-plane Stress I GdaFefiolfl (111) 12.471 SmsGasOn (111) 12.436 -0.035 IL YgGa -gFeg-gon 12.357 YgAlsOn (110) 12.010 0.347 III YaGar-zFea-sou (111) 12.357 'IbsGasOu (111) 12.347 -0.0l0 IV YsGai-zFea-son (111) 12.357 DyaGasou (111) 12.341 0.0l6 N0 At room temperature. The film 12 may also be deposited by sputtering techniques 55 We claim:
1. A method of producing a bubble domain containing film-substrate structure comprising the step of depositing a magnetic film of a single crystal material of the proper orientation and having a negative magnetostriction constant on a substrate in which the magnetic film has a room temperature lattice constant which exceeds the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom.
2. A method of producing a bubble domain containing film-substrate structure comprising the step of depositing an iron garnet film of the proper orientation and having a negative magnetostriction constant on a substrate in which the iron garnet film has a room temperature lattice constant which exceeds the room temperature lattice constant of the substrate by an amount greater than about 0.035 angstrom.
3. A method as described in claim 2 whereby said film is deposited by a chemical vapor deposition technique.
4. A method of producing a bubble domain containing film-substrate structure comprising the step of depositing angstrom.
5. A method as described in claim 4 whereby said substrate is a samarium gallium garnet.
References Cited UNITED STATES PATENTS Mee et al. 117--240 Mee et al. 117--240 Hanak 117-235 Archey 117107 X 6 12/1969 Linares 117-235 X 2/1969 Mee 117-235 X 4/1964 Gambino 117235 3/1971 Moore et a1. 117-235 X OTHER REFERENCES Giess et al., IBM Tech. Dis. Bull., pp. 517, 117-235, vol. 13, N0. 2, July 1970.
10 WILLIAM D. MARTIN, Primary Examiner B. D. PIANALTO, Assistant Examiner US. Cl. X.R.
15 117106' R; 340-174 TF, 174 M UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,' 3a788896 Dated January 29, 1974 Jack E. Mee et a1. Inventor(s) It is certified that error appears in the above-identified patent and that said Letters-Patent are hereby corrected as shown below:
change "b -1.4" and C01 2 1' 56 ft Y G v umn lne a er 3 a Fe O "b l.7" to -l.4 and 1.7 Column 4-,- line 6,
change "titalium" to titanium Signed and sealed this "17th day of September 1974.
(SEAL) Attest:
McCOY M. GIBSON JR. C. MARSHALL DANN v Commissioner of Patents Attesting Officer USCOMM-DC 6O376-P69 us. GOVERNMENT PRINTING OFFICE I969 os66-s34.
F ORM PO-1OSO (10-69)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10178770A | 1970-12-28 | 1970-12-28 |
Publications (1)
Publication Number | Publication Date |
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US3788896A true US3788896A (en) | 1974-01-29 |
Family
ID=22286409
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US00101787A Expired - Lifetime US3788896A (en) | 1970-12-28 | 1970-12-28 | Method for producing bubble domains in magnetic film-substrate structures |
Country Status (6)
Country | Link |
---|---|
US (1) | US3788896A (en) |
CA (1) | CA921775A (en) |
DE (1) | DE2165296C3 (en) |
FR (1) | FR2121046A5 (en) |
GB (1) | GB1367121A (en) |
NL (1) | NL7115050A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3946124A (en) * | 1970-03-04 | 1976-03-23 | Rockwell International Corporation | Method of forming a composite structure |
JPS5312099A (en) * | 1976-07-19 | 1978-02-03 | Philips Nv | Magnetic structure |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL7606482A (en) * | 1976-06-16 | 1977-12-20 | Philips Nv | EenKRISTZL OF CALCIUM-GALLIUM-GERMANIUM GRAINATE, AND SUBSTRATE MANUFACTURED FROM SUCH EenKRISTZL WITH AN EPITAXIALLY GROWN BELDO-MEINFILM. |
DE3234853A1 (en) * | 1982-09-21 | 1984-03-22 | Philips Patentverwaltung Gmbh, 2000 Hamburg | DISC RESONATOR WITH A SUBSTRATE FROM A GRANATE MATERIAL AND WITH AN EPITAXIAL LAYER APPLIED ON THE SUBSTRATE FROM A FERRIMAGNETIC GRANATE MATERIAL |
-
1970
- 1970-12-28 US US00101787A patent/US3788896A/en not_active Expired - Lifetime
-
1971
- 1971-10-04 CA CA124643A patent/CA921775A/en not_active Expired
- 1971-11-02 NL NL7115050A patent/NL7115050A/xx active Search and Examination
- 1971-12-21 GB GB5945371A patent/GB1367121A/en not_active Expired
- 1971-12-23 DE DE2165296A patent/DE2165296C3/en not_active Expired
- 1971-12-28 FR FR7147180A patent/FR2121046A5/fr not_active Expired
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3946124A (en) * | 1970-03-04 | 1976-03-23 | Rockwell International Corporation | Method of forming a composite structure |
JPS5312099A (en) * | 1976-07-19 | 1978-02-03 | Philips Nv | Magnetic structure |
JPS5630690B2 (en) * | 1976-07-19 | 1981-07-16 |
Also Published As
Publication number | Publication date |
---|---|
FR2121046A5 (en) | 1972-08-18 |
DE2165296C3 (en) | 1974-09-26 |
DE2165296B2 (en) | 1974-01-31 |
DE2165296A1 (en) | 1972-07-13 |
NL7115050A (en) | 1972-06-30 |
GB1367121A (en) | 1974-09-18 |
CA921775A (en) | 1973-02-27 |
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