CA1079515A - Post growth adjustment of magnetic propeties of germanium substituted garnet compositions - Google Patents
Post growth adjustment of magnetic propeties of germanium substituted garnet compositionsInfo
- Publication number
- CA1079515A CA1079515A CA260,124A CA260124A CA1079515A CA 1079515 A CA1079515 A CA 1079515A CA 260124 A CA260124 A CA 260124A CA 1079515 A CA1079515 A CA 1079515A
- Authority
- CA
- Canada
- Prior art keywords
- magnetic
- film
- garnet
- iron
- ions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
- C04B35/2675—Other ferrites containing rare earth metals, e.g. rare earth ferrite garnets
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Thin Magnetic Films (AREA)
- Compounds Of Iron (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The magnetic properties of germanium substituted garnet compositions are made adjustable by heat treatment after crystal growth by inclusion in the garnet composition of a small percentage of adjustment-permitting ions whose distribution between tetrahedral and octahedral lattice sites can be reversibly changed by post-growth heat treatment of the garnet material. Post growth annealing of the film results in redistribution of adjustment-permitting ions between tetrahedral and octahedral lattice sites with a consequent change in magnetic properties.
The magnetic properties of germanium substituted garnet compositions are made adjustable by heat treatment after crystal growth by inclusion in the garnet composition of a small percentage of adjustment-permitting ions whose distribution between tetrahedral and octahedral lattice sites can be reversibly changed by post-growth heat treatment of the garnet material. Post growth annealing of the film results in redistribution of adjustment-permitting ions between tetrahedral and octahedral lattice sites with a consequent change in magnetic properties.
Description
a5~L5 BACKGROUND OF THE INVENTION
lo Field of the Invention The invention relates to the field of magnetic garnet ccmpositions and more particularly to means of adjusting the maqnetic properties of the garnet compositions.
lo Field of the Invention The invention relates to the field of magnetic garnet ccmpositions and more particularly to means of adjusting the maqnetic properties of the garnet compositions.
2. Prior Art In order to produce normal magnetic bubble domains in garnet compo-sitions, it is necessary to reduce magnetization of a garnet such as yttrium iron garnet (YIG) (Y3Fe5O12) by substitution of other ions for either the yttrium or the iron. It is common practice in the prior art to substitute non-magnetic ions for iron ions in order to reduce the magnetization of the material. Iron ions occupy two different types of lattice sites within a garnet crystal. These are the octahedral and tetrachedral lattice sitesO Substitution of non-magnetic ions on the tetrahedral iron lattice sites lowers the magnetization of the material~
while substitution of non-magnetic ions on the octahedral iron lattice sites raises the magnetization. ~he Neel temperature (the temperature at which the garnet material ceases to act as a magnetic material) is reduced by substitution for iron on either type of lattice site and the more substitution there is ~or iron the more the Neel temperature is re-duced. A high Neel temperature is desirable for extended operating tem~
perature range of bubble domain memories.
Aluminum and gallium are the commonly used non-magnetic ions which substitute on both octahedral and tetrahedral lattice sites with the result that in order to produce a desired reduction in the magnetiza-tion o~ the garnet composltion, a larger amount of substitution ~ox iron must take place than would be required if the ions substituted only on : : -the tetrahedral iron lattice sites. ThiS ~reater substitution for iron results in a larger reduction in the Neel temperature than would other~
wlse result.
' .' ' ~-:
' ':
"
' ' : :, . . . . ... . . . . ~ . , . . ~ . . . . . .. . .. . . .
5~S
The problem of large substitution and resulting large reduction in the Neel temperature has been minimized through the use of substitution ions which have a strong preference for the tetrahedral iron lattice sites Germanium, silicon and vanadium ions appear to substitute almost exclusively on the tetrahedral iron lattice sites with a consequent minimum reduction in the Neel temperature of the garnet material for a given reduction in magnetization of the material.
Unfortunately, the quantity of germanium, silicon or vanadium substitution is dependent on the growth rate of the garnet, melt composi-tion and other factors which are difficult to control. Consequently germanium, silicon or vanadium substituted garnet compositions are diffi-cult to grow with precisely repeatable magnetic properties. Many appli-cations for garnet thin films such as magnetic bubble domain devices require that there be a minimal variation in the magnetic properties from film to film. Because of various influences on the amount of sub-stitution of germanium for iron in a garnet composition such close toler-ances have bee~ difficult of achievement.
.
SUMMARY OF THE INVE~ION ~, The inventlon overcomes the proble~s ~ film to film variations of magnetic prvperties of germanlum~ silicon or vanadium substituted garnet compositions by inclusion in the garnet composltion of 6mall quantitles o~ ad~ustment-permittin~ ions whose dlstr~bution between tetrahedral iro~ lat-tice sites and octahedral iron lattice sites can be re~ersibly cha~ged by post-growth heat trestment of the garnet material.
~t is pre~erred to utillze ions which demonstrate a decided but not exclusive prefere~ce for the tetrahedral iron lattice sites ~ince this allow~ po~t ~ro~th adJust~ent with a minimum additional reduction in the ~eel temperature. The percentage of the ad~ustment-permitting ion which ~s located on tetrahedral lattice sites is a ~unction o~ the post-growth thermal history of a garnet material. When a garnet film is annealed at hlgh temperatures, the percentage o~ the ad~ustment-permitting ions which are located on tetrahedral lattice ~ites decrea~es and produces a corre~ponding increase in`the magneti2ation of the film. Thus, by -the addition o~ small quantit1es of sd~ustment-permitting ions to the garnet composition, the magnetlc properties of the compositlo~ may be ad~usted after growth through the anneal~ng of the films.
~ ~ _4_ ~ ~7~515 The invention can be defined as a method of providing a magnetic garnet bubble domain material having desired magnetic characteristics suitable for use in magnetic bubble domain systems which require substantially identical magnetic characteristics from production lot to production lot, said method comprising: selecting a substituted magnetic yttrium iron garnet composition for the bubble domain film which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion selected from the group consisting of germanium, ; siIicon and vanadium which substitutes ~or iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non- ~
magnetic ion selected from the group consisting of aluminum ~.
and gallium which substitutes for iron on both the octrahedral and tetrahedral lattice sites and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjust-ment of the magnetic properties of the film by annealing; :
including ions of additional elements each of which partially ;::
, substites for yttrium to tailor the overall characteristics `~ of the magnetic garnet bubble domain film so as to yield an effective bubble domain film; growing the film on a mono- ::
crystalline gadolinium gallium garnet substra~e; measuring the post growth magnetic properties of the garnet film; and annealing the film at a temperature and for a period of time which modifies the magnetic characteristics of the film to ~ - 4a -. ~ ,.
79S~5 the extent necessary to achieve the desired ~haracteristics.
The invention also consists of a magnetic garnet bubble domain composite comprising: a monocr~stalline gadolinium gallium garnet substrate; a monocrystalLine garnet magnetic bubble domain fi].m epitaxially disposed on said substrate, said film having desired magnetic characteristics suitable for use in magnetic bubble domain systems which can be modified after growth in order that the magnetic characteristics of a first production lot which differ from lC those of a second production lot may be modified to be sub-stantially identical to those of the second lot; said magnetic ...
bubble domain film being a substituted magnetic yttrium iron garnet which includes ions of at least two elements as :~
substituents for iron, the ions of a first of said elements being a non-magnetic ion which substitues for iron substantially :.
exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minumum reduction in the Neel temperature of the magnetic garnet, the ; ions of a second of said elements being a non-magnetic ion which substitutes for iron on both the octrahedral and tetrahedral iron lattice sites of the garnet and whose dis-tribution between the octrahedral and tetrahedral lattice sites . can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adiustment of the magneticproperties of the film by annealing; said first ion selected from the group con~
sisting of germanium, silicon and vanadium; said s~cond ion -~
selected from the group consisting of gallium and aluminum, said film composition including addltional ions each of which ¦ - 4b - :
, ~1~79S~5 partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film; said second ion being present in a formula amount of substantially 5~ of the formula amount of said first ion.
- 4c -~;
- - - . - - ~ ... . . .. . .
~C17~5~5 DE~AIL3D Dæ CRlPTIO~ OF THE PREFERRED EMBODIMENT
An exemplary film in accordance with the invention comprises Yl.95smo.locao.95Fe4.ooGeo.95Alo.o5ol2 A fllm of this nominal composi-tion may be grown from a melt comprising 7.0434gm Y203; 1.3854gm S~ 03;
19.7112gm CaO; 20.3014gm GeO2; 185.218~gm F~ 03; 0.6000gm A1203;
78.9227gm ~23; 1513.54gm PbO. This compo~ition results in a decreased magnetization which i6 suitable for the formation of magnetic bubble domalns. Such a film grown at a temperature of' 911 degrees centigrade on a gadolinium galllum garnet sub6titute was caFable o~ supporting bubble domains having a diameter o~ 5.9 micrometer with a oollap~e field o~ 62 Oe. Appropriate temp~rature annealing of the film can increase or decrease the bubble diameter and correspondingly decrease or increase the collapse ~ield. Table I tabulates the bubble diameter and collapse field a~ a i~unction o~ the last annealing temperature. A period of approxima'e-ly eight hours at the specified te~perature was utilized to anneal the ~ilm.
A~n~ 6 5A rer~ e ~C
.: ~ __ Strlp width or bubble diameter 7.o 6-5 6.o 5 9 5.2 (~m) 20 Collapse ~ield (Oe) 5 52 61 62 71 . ~
It will be understood, that other non-magnetlc ions having a sub-stantially exclusive preference for tetrahedral lattice sites suck as sillcon and vanadium may be utilized instead of the germanium and other ad~ustment-permitting ions such as gallium may be utilized instead ~
25 the aluminu~ of the exemplary embodime~t. It is preferred that the ad~ust-ment-permdtting lons have a substantial preference for the tetrah@~ral lat~ice siie in order ~o minimize the ~eel temperature reduction which is - ~5~
... ... . ... , . . .. ... ...... .. , . , - .
;i L5 induced by the adjustment producing ions. However, it will be under~
stood that adjustment permitting ions which do not have a strong prefer- -ence for the tetrahedral site may be utilized with a consequent sacrifice in the Neel temperature.
Another composition in accordance with the invention which is suitable for use as a bubble domain material is Yl 88Euo 20CaO 92Fe4 03 GeO 92Alo~o5 12 If it is desired to increase rather than decrease the magneti7-ation of the garnet composition through substit.ution, elements such as scandium, indium and chromium which apparently occupy only octrahedral lattice sites may be utilized to achieve the increase in magnetization.
Adjustability of the magnetic properties of the garnet is preferably - obtained by inclusion of a small percentage of adjustment-permitting (non-magnetic) ions such as tin and titanium which e~hibit a substantial preference for the octahedral iron lattice sites but whose distribution between octahedral iron lattice sites and tetrahedral iron lattice sites can be reversibly changed by post~growth heat treatment of the garnet material ~owever, adjustment~permitting ions which do not have a substantial preference for octahedral iron lattice sites may be utilized, althou~h their use will result in an additional reduction in the Neel temperature of the garnet.
This technique is use~ul both with g æ net films and bulk garnet material.
Where cations having a valence other than ~3 are substituted into the garnet composition, a charge compensating ion should also be substituted to maintain charge neutrality.
A technique which allows post-growth adjustment of the magnetic properties of germanium substituted type garnet compositions has been described, as have several advantageous compositions~ Those skilled in the art may be able to vary the specifics of the preferred ~mbodiments ; without departing from the scope of the in~ention which is de~ined by the appended claims.
~ 6 - ;
while substitution of non-magnetic ions on the octahedral iron lattice sites raises the magnetization. ~he Neel temperature (the temperature at which the garnet material ceases to act as a magnetic material) is reduced by substitution for iron on either type of lattice site and the more substitution there is ~or iron the more the Neel temperature is re-duced. A high Neel temperature is desirable for extended operating tem~
perature range of bubble domain memories.
Aluminum and gallium are the commonly used non-magnetic ions which substitute on both octahedral and tetrahedral lattice sites with the result that in order to produce a desired reduction in the magnetiza-tion o~ the garnet composltion, a larger amount of substitution ~ox iron must take place than would be required if the ions substituted only on : : -the tetrahedral iron lattice sites. ThiS ~reater substitution for iron results in a larger reduction in the Neel temperature than would other~
wlse result.
' .' ' ~-:
' ':
"
' ' : :, . . . . ... . . . . ~ . , . . ~ . . . . . .. . .. . . .
5~S
The problem of large substitution and resulting large reduction in the Neel temperature has been minimized through the use of substitution ions which have a strong preference for the tetrahedral iron lattice sites Germanium, silicon and vanadium ions appear to substitute almost exclusively on the tetrahedral iron lattice sites with a consequent minimum reduction in the Neel temperature of the garnet material for a given reduction in magnetization of the material.
Unfortunately, the quantity of germanium, silicon or vanadium substitution is dependent on the growth rate of the garnet, melt composi-tion and other factors which are difficult to control. Consequently germanium, silicon or vanadium substituted garnet compositions are diffi-cult to grow with precisely repeatable magnetic properties. Many appli-cations for garnet thin films such as magnetic bubble domain devices require that there be a minimal variation in the magnetic properties from film to film. Because of various influences on the amount of sub-stitution of germanium for iron in a garnet composition such close toler-ances have bee~ difficult of achievement.
.
SUMMARY OF THE INVE~ION ~, The inventlon overcomes the proble~s ~ film to film variations of magnetic prvperties of germanlum~ silicon or vanadium substituted garnet compositions by inclusion in the garnet composltion of 6mall quantitles o~ ad~ustment-permittin~ ions whose dlstr~bution between tetrahedral iro~ lat-tice sites and octahedral iron lattice sites can be re~ersibly cha~ged by post-growth heat trestment of the garnet material.
~t is pre~erred to utillze ions which demonstrate a decided but not exclusive prefere~ce for the tetrahedral iron lattice sites ~ince this allow~ po~t ~ro~th adJust~ent with a minimum additional reduction in the ~eel temperature. The percentage of the ad~ustment-permitting ion which ~s located on tetrahedral lattice sites is a ~unction o~ the post-growth thermal history of a garnet material. When a garnet film is annealed at hlgh temperatures, the percentage o~ the ad~ustment-permitting ions which are located on tetrahedral lattice ~ites decrea~es and produces a corre~ponding increase in`the magneti2ation of the film. Thus, by -the addition o~ small quantit1es of sd~ustment-permitting ions to the garnet composition, the magnetlc properties of the compositlo~ may be ad~usted after growth through the anneal~ng of the films.
~ ~ _4_ ~ ~7~515 The invention can be defined as a method of providing a magnetic garnet bubble domain material having desired magnetic characteristics suitable for use in magnetic bubble domain systems which require substantially identical magnetic characteristics from production lot to production lot, said method comprising: selecting a substituted magnetic yttrium iron garnet composition for the bubble domain film which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion selected from the group consisting of germanium, ; siIicon and vanadium which substitutes ~or iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non- ~
magnetic ion selected from the group consisting of aluminum ~.
and gallium which substitutes for iron on both the octrahedral and tetrahedral lattice sites and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjust-ment of the magnetic properties of the film by annealing; :
including ions of additional elements each of which partially ;::
, substites for yttrium to tailor the overall characteristics `~ of the magnetic garnet bubble domain film so as to yield an effective bubble domain film; growing the film on a mono- ::
crystalline gadolinium gallium garnet substra~e; measuring the post growth magnetic properties of the garnet film; and annealing the film at a temperature and for a period of time which modifies the magnetic characteristics of the film to ~ - 4a -. ~ ,.
79S~5 the extent necessary to achieve the desired ~haracteristics.
The invention also consists of a magnetic garnet bubble domain composite comprising: a monocr~stalline gadolinium gallium garnet substrate; a monocrystalLine garnet magnetic bubble domain fi].m epitaxially disposed on said substrate, said film having desired magnetic characteristics suitable for use in magnetic bubble domain systems which can be modified after growth in order that the magnetic characteristics of a first production lot which differ from lC those of a second production lot may be modified to be sub-stantially identical to those of the second lot; said magnetic ...
bubble domain film being a substituted magnetic yttrium iron garnet which includes ions of at least two elements as :~
substituents for iron, the ions of a first of said elements being a non-magnetic ion which substitues for iron substantially :.
exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minumum reduction in the Neel temperature of the magnetic garnet, the ; ions of a second of said elements being a non-magnetic ion which substitutes for iron on both the octrahedral and tetrahedral iron lattice sites of the garnet and whose dis-tribution between the octrahedral and tetrahedral lattice sites . can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adiustment of the magneticproperties of the film by annealing; said first ion selected from the group con~
sisting of germanium, silicon and vanadium; said s~cond ion -~
selected from the group consisting of gallium and aluminum, said film composition including addltional ions each of which ¦ - 4b - :
, ~1~79S~5 partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film; said second ion being present in a formula amount of substantially 5~ of the formula amount of said first ion.
- 4c -~;
- - - . - - ~ ... . . .. . .
~C17~5~5 DE~AIL3D Dæ CRlPTIO~ OF THE PREFERRED EMBODIMENT
An exemplary film in accordance with the invention comprises Yl.95smo.locao.95Fe4.ooGeo.95Alo.o5ol2 A fllm of this nominal composi-tion may be grown from a melt comprising 7.0434gm Y203; 1.3854gm S~ 03;
19.7112gm CaO; 20.3014gm GeO2; 185.218~gm F~ 03; 0.6000gm A1203;
78.9227gm ~23; 1513.54gm PbO. This compo~ition results in a decreased magnetization which i6 suitable for the formation of magnetic bubble domalns. Such a film grown at a temperature of' 911 degrees centigrade on a gadolinium galllum garnet sub6titute was caFable o~ supporting bubble domains having a diameter o~ 5.9 micrometer with a oollap~e field o~ 62 Oe. Appropriate temp~rature annealing of the film can increase or decrease the bubble diameter and correspondingly decrease or increase the collapse ~ield. Table I tabulates the bubble diameter and collapse field a~ a i~unction o~ the last annealing temperature. A period of approxima'e-ly eight hours at the specified te~perature was utilized to anneal the ~ilm.
A~n~ 6 5A rer~ e ~C
.: ~ __ Strlp width or bubble diameter 7.o 6-5 6.o 5 9 5.2 (~m) 20 Collapse ~ield (Oe) 5 52 61 62 71 . ~
It will be understood, that other non-magnetlc ions having a sub-stantially exclusive preference for tetrahedral lattice sites suck as sillcon and vanadium may be utilized instead of the germanium and other ad~ustment-permitting ions such as gallium may be utilized instead ~
25 the aluminu~ of the exemplary embodime~t. It is preferred that the ad~ust-ment-permdtting lons have a substantial preference for the tetrah@~ral lat~ice siie in order ~o minimize the ~eel temperature reduction which is - ~5~
... ... . ... , . . .. ... ...... .. , . , - .
;i L5 induced by the adjustment producing ions. However, it will be under~
stood that adjustment permitting ions which do not have a strong prefer- -ence for the tetrahedral site may be utilized with a consequent sacrifice in the Neel temperature.
Another composition in accordance with the invention which is suitable for use as a bubble domain material is Yl 88Euo 20CaO 92Fe4 03 GeO 92Alo~o5 12 If it is desired to increase rather than decrease the magneti7-ation of the garnet composition through substit.ution, elements such as scandium, indium and chromium which apparently occupy only octrahedral lattice sites may be utilized to achieve the increase in magnetization.
Adjustability of the magnetic properties of the garnet is preferably - obtained by inclusion of a small percentage of adjustment-permitting (non-magnetic) ions such as tin and titanium which e~hibit a substantial preference for the octahedral iron lattice sites but whose distribution between octahedral iron lattice sites and tetrahedral iron lattice sites can be reversibly changed by post~growth heat treatment of the garnet material ~owever, adjustment~permitting ions which do not have a substantial preference for octahedral iron lattice sites may be utilized, althou~h their use will result in an additional reduction in the Neel temperature of the garnet.
This technique is use~ul both with g æ net films and bulk garnet material.
Where cations having a valence other than ~3 are substituted into the garnet composition, a charge compensating ion should also be substituted to maintain charge neutrality.
A technique which allows post-growth adjustment of the magnetic properties of germanium substituted type garnet compositions has been described, as have several advantageous compositions~ Those skilled in the art may be able to vary the specifics of the preferred ~mbodiments ; without departing from the scope of the in~ention which is de~ined by the appended claims.
~ 6 - ;
Claims (6)
1. A method of providing a magnetic garnet bubble domain material having desired magnetic characteristics suitable for use in magnetic bubble domain systems which require sub-stantially identical magnetic characteristics from production lot to production lot, said method comprising:
selecting a substituted magnetic yttrium iron garnet composition for the bubble domain film which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion selected from the group consisting of germanium, silicon and vanadium which substitutes for iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non-magnetic ion selected from the group consisting of aluminum and gallium which substitutes for iron on both the octrahedral and tetrahedral lattice sites and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjustment of the magnetic properties of the film by annealing;
including ions of additional elements each of which partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film;
growing the film on a monocrystalline gadolinium gallium garnet substrate;
measuring the post growth magnetic properties of the garnet film; and annealing the film at a temperature and for a period of time which modifies the magnetic characteristics of the film to the extent necessary to achieve the desired characteristics.
selecting a substituted magnetic yttrium iron garnet composition for the bubble domain film which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion selected from the group consisting of germanium, silicon and vanadium which substitutes for iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non-magnetic ion selected from the group consisting of aluminum and gallium which substitutes for iron on both the octrahedral and tetrahedral lattice sites and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjustment of the magnetic properties of the film by annealing;
including ions of additional elements each of which partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film;
growing the film on a monocrystalline gadolinium gallium garnet substrate;
measuring the post growth magnetic properties of the garnet film; and annealing the film at a temperature and for a period of time which modifies the magnetic characteristics of the film to the extent necessary to achieve the desired characteristics.
2. A magnetic garnet bubble domain composite comprising:
a monocrystalline gadolinium gallium garnet substrate;
a monocrystalline garnet magnetic bubble domain film epitaxially disposed on said substrate, said film having desired magnetic characteristics suitable for use in magnetic bubble domain systems which can be modified after growth in order that the magnetic characteristics of a first production lot which differ from those of a second production lot may be modified to be substantially identical to those of the second lot;
said magnetic bubble domain film being a substituted magnetic yttrium iron garnet which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion which sub-stitutes for iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non-magnetic ion which substitutes for iron on both the octrahedral and tetrahedral iron lattice sites of the garnet and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjustment of the magnetic properties of the film by annealing;
said first ion selected from the group consisting of germanium, silicon and vanadium, said second ion selected from the group consisting of gallium and aluminum;
said film composition including additional ions each of which partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film;
said second ion being present in a formula amount of substantially 5% of the formula amount of said first ion.
a monocrystalline gadolinium gallium garnet substrate;
a monocrystalline garnet magnetic bubble domain film epitaxially disposed on said substrate, said film having desired magnetic characteristics suitable for use in magnetic bubble domain systems which can be modified after growth in order that the magnetic characteristics of a first production lot which differ from those of a second production lot may be modified to be substantially identical to those of the second lot;
said magnetic bubble domain film being a substituted magnetic yttrium iron garnet which includes ions of at least two elements as substituents for iron, the ions of a first of said elements being a non-magnetic ion which sub-stitutes for iron substantially exclusively on the tetrahedral iron lattice site of the garnet in order to obtain a desired magnetization with a minimum reduction in the Neel temperature of the magnetic garnet, the ions of a second of said elements being a non-magnetic ion which substitutes for iron on both the octrahedral and tetrahedral iron lattice sites of the garnet and whose distribution between the octrahedral and tetrahedral lattice sites can be controlled by post growth annealing of the garnet film, the quantity of said second ion being sufficient to allow post growth adjustment of the magnetic properties of the film by annealing;
said first ion selected from the group consisting of germanium, silicon and vanadium, said second ion selected from the group consisting of gallium and aluminum;
said film composition including additional ions each of which partially substitutes for yttrium to tailor the overall characteristics of the magnetic garnet bubble domain film so as to yield an effective bubble domain film;
said second ion being present in a formula amount of substantially 5% of the formula amount of said first ion.
3. The composite recited in Claim 2 wherein said first ion is germanium and said second ion is aluminum.
4. The composite recited in Claim 3 wherein said film composition is substantially Y1.95Sm0.10Ca0.95Fe4.00Ge0.95 Al0.05O12.
5. A magnetic bubble domain composite comprising a monocrystalline gadolinium gallium garnet substrate having a monocrystalline garnet magnetic bubble domain film epitaxially deposited thereon, the magnetic properties of said film being reversibly adjustable by heat treatment of the composite to modify the distribution of the aluminum ions between the octrahedral and tetrahedral iron lattice sites in order to modify the strip width of magnetic stripe domains in said film, said film having substantially the formula Y1.95SM0.10Ca0.95Fe4.00Ge0.95Al0.05O12.
6. A magnetic bubble domain composite comprising:
a monocrystalline gadolinium gallium garnet substrate;
a magnetic garnet bubble domain film epitaxially disposed on said substrate, the magnetic properties of said film being reversibly adjustable by heat treatment of the composite;
said film exhibiting a minimal reduction in the Neel temperature of the film from the Neel temperature of Y3Fe5O12; and the film having the formula Y1.95Sm0.10Ca0.95Fe4.00 Ge0.95Al0.05O12 in order that the magnetic properties may be reversibly adjusted by heat treatment to modify the distribution of aluminum ions between the tetrahedral iron lattice sites in order to modify the strip width of magnetic stripe domains in said film while the germanium ions remain substantially exclusively on a tetrahedral iron lattice site whereby a minimal reduction in the Neel temperature occurs for the attainment of the desired strip width.
a monocrystalline gadolinium gallium garnet substrate;
a magnetic garnet bubble domain film epitaxially disposed on said substrate, the magnetic properties of said film being reversibly adjustable by heat treatment of the composite;
said film exhibiting a minimal reduction in the Neel temperature of the film from the Neel temperature of Y3Fe5O12; and the film having the formula Y1.95Sm0.10Ca0.95Fe4.00 Ge0.95Al0.05O12 in order that the magnetic properties may be reversibly adjusted by heat treatment to modify the distribution of aluminum ions between the tetrahedral iron lattice sites in order to modify the strip width of magnetic stripe domains in said film while the germanium ions remain substantially exclusively on a tetrahedral iron lattice site whereby a minimal reduction in the Neel temperature occurs for the attainment of the desired strip width.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US61926975A | 1975-10-03 | 1975-10-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1079515A true CA1079515A (en) | 1980-06-17 |
Family
ID=24481187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA260,124A Expired CA1079515A (en) | 1975-10-03 | 1976-08-30 | Post growth adjustment of magnetic propeties of germanium substituted garnet compositions |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5245095A (en) |
| CA (1) | CA1079515A (en) |
| FR (1) | FR2326770A1 (en) |
| GB (1) | GB1564014A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5518095A (en) * | 1978-07-27 | 1980-02-07 | Nec Corp | Cilindrical magnetic domain element |
| DE2941994A1 (en) * | 1979-10-17 | 1981-04-30 | Philips Patentverwaltung Gmbh, 2000 Hamburg | METHOD FOR PRODUCING A MATERIAL FOR RESONANCE FREQUENCIES ABOVE 100 MHz |
| JPS5972707A (en) * | 1982-10-20 | 1984-04-24 | Hitachi Ltd | Garnet film for magnetic bubble element |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1239227B (en) * | 1964-04-04 | 1967-04-20 | Telefunken Patent | Process for the production of magnetic materials with low temperature dependence of the saturation magnetization for use at microwave frequencies |
| US3759745A (en) * | 1971-07-14 | 1973-09-18 | Bell Telephone Labor Inc | Hydrogen annealing of substituted magnetic garnets and materials so produced |
| US3845477A (en) * | 1972-11-24 | 1974-10-29 | Bell Telephone Labor Inc | Method for controlling magnetization in garnet material and devices so produced |
| US3886533A (en) * | 1973-07-20 | 1975-05-27 | Bell Telephone Labor Inc | Magnetic devices utilizing garnet epitaxial material |
-
1976
- 1976-08-30 CA CA260,124A patent/CA1079515A/en not_active Expired
- 1976-09-03 GB GB3666176A patent/GB1564014A/en not_active Expired
- 1976-09-21 JP JP11433476A patent/JPS5245095A/en active Pending
- 1976-10-01 FR FR7629699A patent/FR2326770A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5245095A (en) | 1977-04-08 |
| FR2326770A1 (en) | 1977-04-29 |
| GB1564014A (en) | 1980-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Park et al. | Nonstoichiometry and the long‐range cation ordering in crystals of (Na1/2Bi1/2) TiO3 | |
| CH696907A5 (en) | A process for the manufacture of hexagonal monocrystals and their use as a substrate for semiconductor devices. | |
| CA1079515A (en) | Post growth adjustment of magnetic propeties of germanium substituted garnet compositions | |
| DE2533352A1 (en) | METHOD OF MANUFACTURING FERROELECTRIC CRYSTALLINE MATERIAL | |
| DE2703518A1 (en) | PROCESS FOR ACCELERATED GROWING OF CRYSTALS FROM THE GAS PHASE AND PRODUCTS MANUFACTURED BY THIS PROCESS | |
| KR0143799B1 (en) | Single crystal growth method for bariumtitanikm oxide using noncrystalline solio growth | |
| DE60105228T2 (en) | Material for bismuth substituted garnet thick film and related manufacturing process | |
| LINARES | Substitution of Aluminum and Gallium in Single‐Crystal Yttrium Iron Garnets | |
| DE2418711A1 (en) | Single crystals of bismuth rare-earth garnets - lead-free bismuth gadolinium iron garnets with high faraday effect | |
| US4468438A (en) | Garnet epitaxial films with high Curie temperatures | |
| US4292119A (en) | Growth of single-crystal 2PbO.Fe2 O3 | |
| US4293372A (en) | Growth of single-crystal magnetoplumbite | |
| KR100326279B1 (en) | Solid State Single Crystal Growth Of BaTiO3 | |
| Park et al. | Phase transition of ferroelectric (Na/sub 1/2/Bi/sub 1/2/) TiO/sub 3 | |
| JPH0793212B2 (en) | Oxide garnet single crystal | |
| JPS63195198A (en) | Production of lithium niobate single crystal thin film | |
| US4555374A (en) | Method of manufacturing a disc resonator | |
| JPS62216310A (en) | Magneto-optical crystal growth method | |
| JPS6389496A (en) | Production of compound semiconductor | |
| Dobrovinskaya et al. | Structural defects and their genesis in corundum monocrystals | |
| JP2770572B2 (en) | Method for producing semi-insulating GaAs single crystal | |
| JPS63230595A (en) | Yttrium-iron garnet single crystal and production thereof | |
| JP2794673B2 (en) | Oxide garnet single crystal magnetic film and method of manufacturing the same | |
| KR100540449B1 (en) | Manufacturing method of garnet single crystal and a garnet single crystal manufactured by the method | |
| JPH0867600A (en) | Production of bismuth-substituted rare-earth iron garnet single crystal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |