US2579267A - Material having improved magnetic property - Google Patents

Material having improved magnetic property Download PDF

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Publication number
US2579267A
US2579267A US795046A US79504647A US2579267A US 2579267 A US2579267 A US 2579267A US 795046 A US795046 A US 795046A US 79504647 A US79504647 A US 79504647A US 2579267 A US2579267 A US 2579267A
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Prior art keywords
beo
values
mole percent
oxide
materials
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US795046A
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Humboldt W Leverenz
Imre J Hegyi
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RCA Corp
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RCA Corp
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Priority to US795046A priority patent/US2579267A/en
Priority to ES0186355A priority patent/ES186355A1/es
Priority to FR978215D priority patent/FR978215A/fr
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    • 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
    • C04B35/2608—Compositions containing one or more ferrites of the group comprising manganese, zinc, nickel, copper or cobalt and one or more ferrites of the group comprising rare earth metals, alkali metals, alkaline earth metals or lead

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  • This invention relates to materials having improved magnetic properties. These materials may have unusually high values of magnetic permeability, or they may have desirably low loss values (high Q factors) at radio frequencies, or a usefully high product of these two values. They may also have desirable properties of magnetostriction and good stability at operating temperatures. They may also have an improved modulus of elasticity and good resistivity.
  • the present invention relates to materials known as ferrites, made by the general method described in co-pending application of H. W. Leverenz and R. L. Harvey entitled Improvement in Magnetic Materials, Serial No. 776,292, filed September 26, 1947, now Patent No. 2,565,861.
  • the present improvement is especially related to the use of beryllium oxide, BeO, either substituted for part of the oxides previously disclosed,
  • One object of the present invention is to prov-y vide compositions having improved magnetici properties.
  • Another object of the invention is to provide materials having controllable and unusually'high values. of magnetic permeability.
  • Another object of the invention is to provide materials having low loss values (high Q factors).
  • Another object of the invention is to provide materials having improved magnetic properties and alsoA high Curie temperatures.
  • Another object of the invention is to provide materials having a desirably wide range of magnetostriction.
  • Another object of the invention is to provide materials having improved magnetic properties along with a desirable modulus of elasticity.
  • Another object is to provide improved compo-,- sitions of magnetically permeable ferrites which include beryllium oxide as an essential ingredient.
  • Still another object is to provide materials having desirable values of resistivity.
  • this method includes the intimate mixing of ferric oxied and the various other oxides involved. each in a ne state of subdivision, heating, preferably, a compressed body made of these oxides within a range of temperatures 'of about 900 C. to about 1500 C. for about 1 minute to about 5 hours in an oxidizing atmosphere, and then cooling. Longer heating times are required for larger bodies.
  • Optimum conditions of time and temperature of heating will vary with each specific composition possible within the systems of compositions which are a part of the present invention and, with any specific composition, the optimum heating time decreases as the temperature of heating increases. In general, however, some improvement in results is obtained by selecting widely varying times and temperatures within the ranges specied, even though these improvements will not be the maxiof the order of 1200 C. has proved satisfactory, if not always best, with all of the compositions.
  • the oxidizing atmosphere in which the heat- 3 ing of the reaction mixture takes place may be helium or nitrogen, but the improvement is not as great as when an oxidizing atmosphere is used.
  • a reducing it possible to start wvvith a mixture ofkmateatmosphere, such as supplied by carnbon monoxide or hydrogen, in the reaction chamber is distinctly detrimental, if 'materials having high permeability are desired. Therefore, it may bev said that the heating should take place in a nonreducing atmosphere. preferably at atmospheric or higher pressures.
  • the iron may be in the forni of ferrous oxide or magnetite, providing thaty heating takes place in an oxidizing atmosphere, and as the hydroxide, carbonate, etc., if either an oxidizing or a neutral atmosphere ispresent.V
  • the other ingredients may also be present forms such as hydroxides, acetates or carbonates or either lower or higher oxide forms than-'- are present in the nal product, since thesewill revert to the desired oxide form when heated strongly in. the preferred oxidizing atmosphere arid, insme eases, evenin a'neutral'atmosphere.
  • Certain o'f the present compositions' also utilize oxideso'f manganese. This is preferably' present as MnOz the initial mixture but changes to MnO irrtlie reatio'prdct.
  • oinprssed bodies ofv the reactants may be fortified at pressures of, say, 20,000V pounds per square inch and these compressed bodies are treated at' elvatedteriiperatures'in order to impart the desired properties' of increased permeability, low loss, etl, desired iii. the end product.
  • These compressedbodies may also be' formed" by extrusion molding processes at mush liier"pres#A sures. The fact that shaped bodies of the compressed material can be formed without' thepresence' of a permanent binderadds rinih to their improi/'iet over" materials.
  • the ingredientV oxides may be preLheated, .mixed with a',- temporary binder and extrusion molded y and heat treated.
  • In generaLit may be said that'the pressure. of forinshould be siicient to forma closely coherent. bodyV and' the ⁇ pressures used should simply be those. necessary to obtain this result.V
  • reaction product' is pref'- erably, although not necessarily, cooled very rapidly as. by subjecting .it tov a blast of air or quenching in water. Rapid cooling'generally increases the permeability and low loss. qualitiesV above those values obtained when slow coolingis used.
  • the reaction mixture may be compressed into any desired'sh'ape before heating takes place in the reaction chamber.
  • the danger of warping of the compressed bodies, when heated, may be lessened by mixing a small percentage of a lubricant with powdered oxidesbefore compression.
  • the preferred lubricants' are those which are completely burned off during the heat treatment process. Suitable examples are stearic acid and microcrystallinewaxes, such as Carbowax.
  • the present invention relates more specifically to the use of beryllium oxide in ferrite bodies, prepared as described.
  • the' additiorjofiberylliumoxide produces desirablei improvements not obtainable when mix/L" tures ofl oxides; not includingberyl-liumoxide; are used; 5
  • Table III values are given for a system comprising BeOzZnOzMgOzFezOa. These values were obtained by crystallization at 130()u C". in an oxygen atmosphere.
  • Table III Table IV contains values obtained for asystem comprising BeO:ZnO:CuO:Fe2O2. The values were measured for materials crystallized at 1200 C. in an oxygen atmosphere.
  • onincOrpora-ting Bco. occur in those compositions having Curie tern- -v Be@ Odo M302 F6201 Q 1 Q peratures near roomtemperature.
  • the incorporation of BeO benegj gg cially raises the Curie temperature, as well as 0.10 0.15 0.2 5 0. 50 10.5r 05 080 the product ILQ.
  • able VII shows the effects of adding BeO to gure shows the extent of improvement that it the system MnO:ZnO:CdO:Fe2O3 to form a penis Ossrible to. Obtain .by addin an optimum system including BeO.
  • cent NiO, and 35 mole percent ZnO can have its 0 0,125 0.125 0.25 0.5 1.5 4 29 447 4Q product increased by about 530 units
  • an optimum amount of BeO is included in the composition ,before crystallization. It will be not- In all Aof the above systems, the beryllium oxide ed further that, when the compositions contain was added to the mixture before the mixture was about mole percent Fe2O1, the maximum poscompressed and crystallization carried. out.
  • the addition of BeO may lower the various ternary system ferrites, including BeO, product 10Q; hence, the improved materials are given in Table VIII. It will be noted that should preferably comprise no more than about some significant improvement is obtained in ⁇ almole-percent of iron oxide. Furthermore, most all instances by the addition of BeO alcompositions which have less than about 30 mole- 45 though the percentageof improvement is not as percent of Fe2Os have poor characteristics which great, in general, as when the BeO is added or are generally not improved suiciently by the nsubstitutedv to form a q'uaternary'system.
  • the heating temperature was 1200" C. except that those compositions containing ⁇ N10-were heated at 1400 C., those containing MgO were heated at 1300 C. and those .containing ZnO were heated at 1400" C..
  • the benecial effects of adding BeO (or MgO) to the ferrite compositions may be related to the higher @polarizing power of the Be++ (or l ⁇ /ig-++) ions and the higher melting points of the. BeO (or MgO). .Thenpolarizing power,.for example, is proportionalto q/r, where q is. the valence charge andr vthe ionic radius. Be++ exhibits' an outstandingly high ratio of q/r. Another interesting and important property of compressed bodies made up of compositions fallling within the present invention is that of magnetostriction.
  • Magnetostriction is evidenced by the ability of a bodyto lengthen in one dimension and contract in another direction when subjwjected to a magnetic field. Measurements were made on compressed cores of the materialsinsertedwithin ahollow tube 11/2 inches ⁇ long and ⁇ having 1A; inch outside diameter. The cores were rectangular in cross section and had a length Qf noid of 990 turns of. No. 30copper wire. Measurements were taken using .two different field strengths, namely, y49.0. oersteds (M1) and 150.5 oersteds (M2) The former was obtained by applying abatterycurrentof 0.15 ampere at 1.5 volts and thelater eld was. obtained by applying .a battery. currentof0.46 :ampere at 6 volts tothe solenoid. Y
  • the present invention constitutes the discovery that the addition of beryllium-oxide to crystalline ferrite materials containing atleast one other oxide of a certain group of -oxides results in the formation of materials having improved magnetic properties, especially if compared with the best previously 1known materials .formerly used for the same purposes, ⁇ such as Y.powdered iron.
  • the group Yo1' other oxides yfrom more mav also be'used although, apparently, no
  • compositions may be in any one or more of several categories; hence, whether or not a certain material constitutes an improved product compared with vprior art materials cannot be iudged by any onetest.
  • Certain of the compositions exhibit exceptionally high ⁇ values of magnetic permeability, othersfhave exceptionally low loss factor (high Q), some have a desirably high product of 'these two values, others have desirable magnetostri'ctive properties and still others have lgreat stability-although their permeability or Q values-maynot 'be as high as any one of a number oi .other possible compositions.
  • a composition may have excep tionally high Curie temperature and thus be usefull for certain applications.
  • a composition of matter comprising the reactionY product produced by heating together in a non-reducing atmosphere at ⁇ teiripi-n'atures oi 900 C. to 15'00" C. ⁇ for I1xninute to 5 hours an intimatel :mixture lof from "30 to '70 vmole percent FezOx, 0.2 to 50 mole percent BeO, and the re mainder comprising at least 20 mole jpercent one other oxidefrorn the class consisting of the oxides of manganese, zinc, magnesium, nickel, cadmium and copper.
  • composition according to claim 1, in which the amount of BeO Vis lfrom about 0.2 to about 30 molepercent.
  • a ⁇ composition, of matter comprising the reaction product produced by heating together in a non-reducing atmosphere at' temperatures of a non-reducingatmosphere at temperaturesof 900 C. to r1500i7 C. for 1 minute. to-5 lxoursz an I2 intimatemixturenot.abouto to about '70 mole percent FezOs, about 0.2 'to 50 mole percent BeO, and the remainderv comprising atleast 20 mole percent of two oxides of different Ymetals ⁇ from the class consisting of -oxides of manganese, zinc. magnesium, nickel, copper and cadmium.
  • A-composition-cf matter comprising there- 'action product produced by heating together in a non-reducing atmosphere. for 1 minute'to 5 rhoursfat temperatures of 900 YC. to 1500 C. an
  • An article of manufacture characterized 'by having improved magnetic properties comprising a compressed body of material "of predetermined shape, said material-comprising a reaction product produoedby heatingtogether vin ka non-reducing, atmosphere ata temperature yof 900 C. to
  • An article of manufacture rcharacterized by having improved magnetic properties comprising a compressed body of materialof predetermined shape, said material comprisingv a reaction prodprisilflgpreparing an'intima'te mixture of ⁇ 30 to A7.0
  • mole percent FezOs 0.2 'to 50 :mole percent v'BeO .and at least 20 mole percentcf anY oxide from'the class consisting of Mn02, Z110, MgO, NiO, C and CdO,.compressing said mixture to form V1a. coherent molded body of vpredetermined shape. subjecting said. moldedl body 'to a temperature .of 900 C. to 150GD C.in..a non-reducingatmosphere for 1 minute to 5 hours to form .a Vcrystalline substanceY having ⁇ a deiinite chemical composition, and cooling said ⁇ crystalline substance.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Soft Magnetic Materials (AREA)
  • Compounds Of Iron (AREA)
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US795046A 1947-12-31 1947-12-31 Material having improved magnetic property Expired - Lifetime US2579267A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL75788D NL75788C (en(2012)) 1947-12-31
US795046A US2579267A (en) 1947-12-31 1947-12-31 Material having improved magnetic property
ES0186355A ES186355A1 (es) 1947-12-31 1948-12-21 Un método de preparar materiales magnéticos
FR978215D FR978215A (fr) 1947-12-31 1948-12-24 Matières possédant des propriétés magnétiques améliorées, et procédé de préparation de ces matières

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2828264A (en) * 1954-11-09 1958-03-25 Audax Manufacture process of permanent magnets from sintered mixtures of oxides
US2923684A (en) * 1957-06-19 1960-02-02 Du Pont Tin modified ferromagnetic chromium oxide, its preparation and use in recording members
US2923683A (en) * 1957-06-19 1960-02-02 Du Pont Antimony-modified chromium oxide ferromagnetic compositions, their preparation and use
US2962444A (en) * 1956-01-19 1960-11-29 Centre Nat Rech Scient Ferromagnetic ceramic materials
US2977311A (en) * 1955-02-03 1961-03-28 Centre Nat Rech Scient Ferromagnetic ceramic materials
US2980618A (en) * 1956-05-02 1961-04-18 Centre Nat Rech Scient Ferromagnetic material for gyromagnetic effect
US3031405A (en) * 1956-12-14 1962-04-24 Lignes Telegraph Telephon Ferromagnetic materials having a rectangular hysteresis cycle
US3034986A (en) * 1956-01-03 1962-05-15 Sylvania Electric Prod Ferrite materials
US3034988A (en) * 1958-08-22 1962-05-15 Du Pont Modified chromium oxide ferromagnetic compositions, their preparation and use
US3042617A (en) * 1958-12-31 1962-07-03 Rca Corp Magnetic bodies and methods of preparation thereof
US3169115A (en) * 1960-08-25 1965-02-09 Nippon Electric Co Manganese zinc ferrite containing vanadium pentoxide, silicon dioxide, and indium trioxide
US4023174A (en) * 1958-03-10 1977-05-10 The United States Of America As Represented By The Secretary Of The Navy Magnetic ceramic absorber

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1946964A (en) * 1933-07-11 1934-02-13 Boonton Res Corp Magnetic material and process of making the same
US1976230A (en) * 1930-12-25 1934-10-09 Mitsubishi Electric Corp Permanent magnet and method of manufacturing same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1976230A (en) * 1930-12-25 1934-10-09 Mitsubishi Electric Corp Permanent magnet and method of manufacturing same
US1946964A (en) * 1933-07-11 1934-02-13 Boonton Res Corp Magnetic material and process of making the same

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2828264A (en) * 1954-11-09 1958-03-25 Audax Manufacture process of permanent magnets from sintered mixtures of oxides
US2977311A (en) * 1955-02-03 1961-03-28 Centre Nat Rech Scient Ferromagnetic ceramic materials
US3034986A (en) * 1956-01-03 1962-05-15 Sylvania Electric Prod Ferrite materials
US2962444A (en) * 1956-01-19 1960-11-29 Centre Nat Rech Scient Ferromagnetic ceramic materials
US2980618A (en) * 1956-05-02 1961-04-18 Centre Nat Rech Scient Ferromagnetic material for gyromagnetic effect
US3031405A (en) * 1956-12-14 1962-04-24 Lignes Telegraph Telephon Ferromagnetic materials having a rectangular hysteresis cycle
US2923684A (en) * 1957-06-19 1960-02-02 Du Pont Tin modified ferromagnetic chromium oxide, its preparation and use in recording members
US2923683A (en) * 1957-06-19 1960-02-02 Du Pont Antimony-modified chromium oxide ferromagnetic compositions, their preparation and use
US4023174A (en) * 1958-03-10 1977-05-10 The United States Of America As Represented By The Secretary Of The Navy Magnetic ceramic absorber
US3034988A (en) * 1958-08-22 1962-05-15 Du Pont Modified chromium oxide ferromagnetic compositions, their preparation and use
US3042617A (en) * 1958-12-31 1962-07-03 Rca Corp Magnetic bodies and methods of preparation thereof
US3169115A (en) * 1960-08-25 1965-02-09 Nippon Electric Co Manganese zinc ferrite containing vanadium pentoxide, silicon dioxide, and indium trioxide

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NL75788C (en(2012))
ES186355A1 (es) 1949-03-01
FR978215A (fr) 1951-04-11

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