US2980618A - Ferromagnetic material for gyromagnetic effect - Google Patents
Ferromagnetic material for gyromagnetic effect Download PDFInfo
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- US2980618A US2980618A US656421A US65642157A US2980618A US 2980618 A US2980618 A US 2980618A US 656421 A US656421 A US 656421A US 65642157 A US65642157 A US 65642157A US 2980618 A US2980618 A US 2980618A
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- 230000000694 effects Effects 0.000 title description 10
- 239000003302 ferromagnetic material Substances 0.000 title description 3
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 28
- 239000000463 material Substances 0.000 claims description 23
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 19
- 230000005291 magnetic effect Effects 0.000 claims description 15
- 239000011787 zinc oxide Substances 0.000 claims description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- 239000001301 oxygen Substances 0.000 claims description 11
- 229910010293 ceramic material Inorganic materials 0.000 claims description 10
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 10
- 230000005294 ferromagnetic effect Effects 0.000 claims description 8
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 8
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 8
- 239000007795 chemical reaction product Substances 0.000 claims description 4
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims 2
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 8
- 238000007792 addition Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910001053 Nickel-zinc ferrite Inorganic materials 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 241000656145 Thyrsites atun Species 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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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
- C04B35/265—Compositions containing one or more ferrites of the group comprising manganese or zinc and one or more ferrites of the group comprising nickel, copper or cobalt
Definitions
- the present invention relates to ferromagnetic ceramic material intended for use in devices in which the gyromagnetic effect at hyperfrequencies is required.
- These devices may be, in particular, switches, phase shifters, modulators, routing devices, separators, that is to say, devices having diflerent attenuations in the two directions of transmission of the electromagnetic wave, the above list not being of a limitative nature.
- the properties of the materials will be considered in the particular case of a device making use of the Faraday effect in which a cylindrical rod, of circular cross-section is placed in the axis of a wave guide of circular cross-section and subjected to a steady longitudinal magnetic field.
- the circular wave-guide is connected at each end by suitable transition sections to lengths of rectangular waveguide.
- An electromagnetic wave is propagated in one of the rectangular wave guides in the TE mode, in which the electric vector is parallel to the short side of the guides. This mode is converted in the circular wave guide to the TE mode, and this mode is again converted to the TE mode in the succeeding section of rectangular waveguide.
- the effect of the presence of the ferromagnetic ceramic material subjected to a longitudinal magnetic field is to rgtat e the direction of polarisation of the electromagnetic wave through an angle which is dependent upon the magnetic field within the material, upon the composition of the material and upon the length and the diameter of the rod.
- the rectangular. wave guides are disposed at an angle with respect to one another dependent upon the angle through which the plane of polarisation of the electromagnetic waves is to be rotated.
- the plane of polarisation is rotated in the same direction for both directions of transmission so that waves proceeding from one rectangular wave guide to the other have the plane of polarisation rotated for transmission along the last mentioned wave guide whereas waves proceeding in the reverse direction have the plane of polarisation rotated so that the waves are little or not at all, propagated into the first mentioned wave guide.
- an electromagnetic wave traversing such a device as described above suffers some attenuation and the efiiciency of the device may be measured by the ratio Angular rotation of plane of polarisation Attenuation for a given length of rod of ferromagnetic ceramic materials.
- the efiiciency of a rod of ferromagnetic ceramic material comprising a nickel zinc ferrite having a nickel oxide content between 13 mol percent and 20 mol percent is increased in a device utilising the gyromagnetic effect by incorporating therein between 2 and 20 molar percent of chromic oxide (Cr O
- Cr O chromic oxide
- the remaining material may consist of between 30 and 50 mol percent of ferric oxide with the rest being zinc oxide.
- Fig. 2 shows the effect of different percentage additions of chrornic oxide on the attenuation.
- Fig. l is a curve showing the rotations of the plane of polarisation of rods of the same dimensions but of different ferromagnetic ceramic materials.
- the basic material is a nickel zinc ferrite containing 18 mol percent of NiO, 32 mol percent of ZnO, 50 mol percent of Fe O
- To different batches of this material were added different molar percentages of chromic oxide, in place of an equivalent percentage of Fe O shown as abscissae.
- the angles of rotation of the plane of polarisation for electromagnetic waves of frequency 10,000 mc./s. are given as ordinates. It will be observed that the angle of rotation decreases as the amount of chrornic oxide increases.
- Fig. 2 is a curve showing the attenuation in decibels (as ordinates) for the same materials as in Fig. 1 and it will be noted that the attenuation decreases with increasing content of chromic oxide.
- the eificiency as measured by rotation, per decibel of attenuation is increased by the addition of up to 20 mol percent Cr O Ceramic materials according to the invention may contain between 46 and 54 mol percent of the sum of chromic oxide and ferric oxide, of which between 2 mol percent and 15 mol percent is chromic oxide, between 13 and 20 mol percent of nickel oxide and the remainder Zinc oxide.
- chromic oxide The particular percentage of chromic oxide to be used depends upon the nickel oxide content.
- the shapes of curves such as those in Figs. 1 and 2 are generally the same for all materials according to the invention but vary slightly according to the nickel oxide content.
- the presence of chromic oxide has some effect upon the temperature of heat treatment of the mixture of oxides required to attain a given intensity of magnetic saturation in the material.
- the molecular content of chromic oxide is chosen to realise the test compromise amongst the desired properties for a particular application.
- the gyromagnetic properties of materials according to the invention are defined in a device such as described above making use of the Faraday effect because the results of measurements in such a device are most characteristic of the material, but it is to be understood that materials according to the present invention are of use in any device which makes use of gyromagnetic properties.
- Example 1 In a ball mill, of iron, a mixture of the following constituents is ground for 24 hours in the molecular proportions indicated: NiO, 18%; Cr O 10%; Fe O 41%; Zoo, 31%.
- This product after pressing, is sintered at a temperature of 1250 C. for four hours in an oxygen atmosphere, and then cooled for 16 hours in the same atmosphere.
- a material of this kind employed in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at the frequency of 9,700 mc./s. a rotation of 30 when it is subjected to a longitudinal magnetic field equal to oersted.
- the attenuation of the wave is 0.04 decibel.
- the ellipticity of the emerging wave measured, as explained above, is higher than 30 decibels,
- Example 2 A mixture ofthefollowing composition is ground in the molecular proportions indicated: NiO, 18%; Cr O Fe O 40%; ZnO, 32%.
- This product after pressing, is sintered at a temperature of 1250 C. for four hours in an oxygen atmosphere.
- a material of this kind employed in the form of a circular cylindrical bar 6 mm. in diameter'and 30mm. long, produces at the frequency of 9,700 mc./s. a rotation of 48 when it is subjected to a longitudinal magnetic field equal to 100 oersted. The attenuation of the wave is 0.08 decibel.
- Example 3 The following mixture is ground in the molecular proportions indicated: NiO, 18%; Cr O Fe O 35%; ZnO, 32%.
- This product after pressing, is sintered at a temperature of 1200 C. for four hours in an oxygen atmosphere.
- This material used in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at the frequency of 9,700 mc./s. a rotation of 45 and anattenuation of 0.05 decibel, when subjected to a longitudinal magnetic field equal to 100 orsted.
- Example 4 The following mixture is ground in the molecular proportions indicated: NiO, 17%, Cr O 7%; Fe O 44%; ZnO, 32%. After pressing and sintering at a temperature of 1200 C. for fourhours in an oxygen atmosphere, this material, used-in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at a frequency of 9,700 mc./s. a rotation of 30 and a negligible attenuation, when subjected to a longitudinal magnetic field of 100 oersted.
- Example 5 The following mixture in molecular percentage: NiO, 17%; Cr O 7%; Fe O 44%; ZnO, 32%; is ground, then pressed. It is then sintered at 1200" C. for four hours in an oxygen atmosphere. Used in the form of a circular cylindrical bar 6.5 mm. in diameter and 30 mm. long, this material, subjected to a longitudinal magnetic field of 100 oersted, produces a rotation of 90 and an attenuation of 0.3 decibel.
- Example 6 The following mixture in molecular percentage NiO, 13%; Cr O 5%; Fegog, 49%; ZnO, 33% is ground, pressed and sintered at 1250 C. for 4 hours in an oxygen atmosphere. Used in the form of a circular cylindrical bar 5.3 mm. in diameter and 30 mm. long, this material produces a rotation of 50 for a Wave of 9700 mc./s. an attenuation of 0.17 db and an ellipticity of the emerging wave greater than 35 db when subjected to a longitudinal magnetic field of 100 oersted.
- Example 7 A composition in molecular percentages of NiO, Cr O 20%; Fe O 30%; Z110, 30% sintered for 4 hours at 1200 C. in an oxygen atmosphere and in the form of a circular rod of 6.5 mm. diameter and 30 mm. long gave, at 9700 mc./s. a rotation of an attenuation of 0.09 db and an ellipticity greater than 35 db when subjected to a longitudinal magnetic field of 100 oersted.
- molecular content of chromic oxide may however be chosen to realise the best compromise the particular device contemplated, since theiinvention is not limited to devices of the particular kind described.
- a body of ferromagnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and presenting a low attenuation to said frequencies, said body being the reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 5 to 20 mol. percent of chromic oxide, from 30 to mol. percent of ferric oxide and the remainder zinc oxide, the sum of the chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of the material, said mixture being compressed and sintered at a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen atmosphere for approximately four hours.
- a body of ferromagnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and'presenting a low attenuation to said frequencies, said body being the reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 10 to 20 mol. percent of chromic oxide, from 30 to 50 mol. percent of ferric oxide and the remainder zinc oxide, the sum of the chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of'the material, said mixture being compressed and sintered at a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen atmosphere for approximately four hours.
- a body of ferrogamnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and presenting a low attenuation to said frequencies, said body being the. reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 5 to 15 mol. percent of chromic oxide, from 35 to 49 mol. percent of ferric oxide and the remainder zinc oxide, the sum of the L chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of the material, said mixture being compressed and sinteredat a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen a mosphere for approximately four hours:
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Description
April 1961 c. L. GUILLAUD ETAL 2,980,618
FERROMAGNETIC MATERIAL FOR GYROMAGNETIC EFFECT Filed May 1, 1957 Alfenual/on in dec/be/s ZO'O 0 25 5 /0 /5 2 Inventor (LL. Grumuu RNaukiar Bylmw w A Home y United.
FERROMAGNETIC MATERIAL FOR GYROMAGNETIC EFFECT Charles Louis Guillaud and Roger Vautier, Bellevue, France, assignors to Centre National de la Recherche Scientifique, Paris, France, a French government administration The present invention relates to ferromagnetic ceramic material intended for use in devices in which the gyromagnetic effect at hyperfrequencies is required.
These devices may be, in particular, switches, phase shifters, modulators, routing devices, separators, that is to say, devices having diflerent attenuations in the two directions of transmission of the electromagnetic wave, the above list not being of a limitative nature.
For the purpose of comparison the properties of the materials will be considered in the particular case of a device making use of the Faraday effect in which a cylindrical rod, of circular cross-section is placed in the axis of a wave guide of circular cross-section and subjected to a steady longitudinal magnetic field. The circular wave-guide is connected at each end by suitable transition sections to lengths of rectangular waveguide. An electromagnetic wave is propagated in one of the rectangular wave guides in the TE mode, in which the electric vector is parallel to the short side of the guides. This mode is converted in the circular wave guide to the TE mode, and this mode is again converted to the TE mode in the succeeding section of rectangular waveguide.
The effect of the presence of the ferromagnetic ceramic material subjected to a longitudinal magnetic field is to rgtat e the direction of polarisation of the electromagnetic wave through an angle which is dependent upon the magnetic field within the material, upon the composition of the material and upon the length and the diameter of the rod. The rectangular. wave guides are disposed at an angle with respect to one another dependent upon the angle through which the plane of polarisation of the electromagnetic waves is to be rotated. The plane of polarisation is rotated in the same direction for both directions of transmission so that waves proceeding from one rectangular wave guide to the other have the plane of polarisation rotated for transmission along the last mentioned wave guide whereas waves proceeding in the reverse direction have the plane of polarisation rotated so that the waves are little or not at all, propagated into the first mentioned wave guide.
In addition to a rotation of the plane of polarisation an electromagnetic wave traversing such a device as described above suffers some attenuation and the efiiciency of the device may be measured by the ratio Angular rotation of plane of polarisation Attenuation for a given length of rod of ferromagnetic ceramic materials.
According to the present invention the efiiciency of a rod of ferromagnetic ceramic material comprising a nickel zinc ferrite having a nickel oxide content between 13 mol percent and 20 mol percent is increased in a device utilising the gyromagnetic effect by incorporating therein between 2 and 20 molar percent of chromic oxide (Cr O The remaining materialmay consist of between 30 and 50 mol percent of ferric oxide with the rest being zinc oxide.
aigt
Patented Apr. 18, 196i I "ice The invention will be better understood from the following description taken in conjunction with the accompanying drawings in which Fig. 1 shows the efiect of different percentage additions of chromic oxide on the angle of rotation of plane of polarisation, and
Fig. 2 shows the effect of different percentage additions of chrornic oxide on the attenuation.
Referring to the drawings Fig. l is a curve showing the rotations of the plane of polarisation of rods of the same dimensions but of different ferromagnetic ceramic materials. The basic material is a nickel zinc ferrite containing 18 mol percent of NiO, 32 mol percent of ZnO, 50 mol percent of Fe O To different batches of this material were added different molar percentages of chromic oxide, in place of an equivalent percentage of Fe O shown as abscissae. The angles of rotation of the plane of polarisation for electromagnetic waves of frequency 10,000 mc./s. are given as ordinates. It will be observed that the angle of rotation decreases as the amount of chrornic oxide increases.
Fig. 2 is a curve showing the attenuation in decibels (as ordinates) for the same materials as in Fig. 1 and it will be noted that the attenuation decreases with increasing content of chromic oxide. The eificiency as measured by rotation, per decibel of attenuation is increased by the addition of up to 20 mol percent Cr O Ceramic materials according to the invention may contain between 46 and 54 mol percent of the sum of chromic oxide and ferric oxide, of which between 2 mol percent and 15 mol percent is chromic oxide, between 13 and 20 mol percent of nickel oxide and the remainder Zinc oxide.
The particular percentage of chromic oxide to be used depends upon the nickel oxide content. The shapes of curves such as those in Figs. 1 and 2 are generally the same for all materials according to the invention but vary slightly according to the nickel oxide content. The presence of chromic oxide has some effect upon the temperature of heat treatment of the mixture of oxides required to attain a given intensity of magnetic saturation in the material. In general the molecular content of chromic oxide is chosen to realise the test compromise amongst the desired properties for a particular application.
In the following examples the gyromagnetic properties of materials according to the invention are defined in a device such as described above making use of the Faraday effect because the results of measurements in such a device are most characteristic of the material, but it is to be understood that materials according to the present invention are of use in any device which makes use of gyromagnetic properties.
In the following examples, measurements are also given for the ellipticity of the wave emerging from the circular wave guide. This ellipticity is measured in decibels by the logarithm of the ratio of the maximum power to the minimum power and in the experiments to which the results relate the output rectangular guide was rotated about its axis to determine this ratio.
Example 1.In a ball mill, of iron, a mixture of the following constituents is ground for 24 hours in the molecular proportions indicated: NiO, 18%; Cr O 10%; Fe O 41%; Zoo, 31%. This product, after pressing, is sintered at a temperature of 1250 C. for four hours in an oxygen atmosphere, and then cooled for 16 hours in the same atmosphere. A material of this kind, employed in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at the frequency of 9,700 mc./s. a rotation of 30 when it is subjected to a longitudinal magnetic field equal to oersted. The attenuation of the wave is 0.04 decibel. The ellipticity of the emerging wave measured, as explained above, is higher than 30 decibels,
By-way of comparison,--a material prepared and employed .under. the...same..conditions, but with the following molecular percentages: NiO, 18%; Fe O 51%; ZnO, 31%; produces a rotation of 65 and an attenuation of 0.7 decibel.
Example 2.--A mixture ofthefollowing composition is ground in the molecular proportions indicated: NiO, 18%; Cr O Fe O 40%; ZnO, 32%. This product, after pressing, is sintered at a temperature of 1250 C. for four hours in an oxygen atmosphere. A material of this kind, employed in the form of a circular cylindrical bar 6 mm. in diameter'and 30mm. long, produces at the frequency of 9,700 mc./s. a rotation of 48 when it is subjected to a longitudinal magnetic field equal to 100 oersted. The attenuation of the wave is 0.08 decibel.
By way of comparison a material prepared and employed under the same conditions but with the molecular percentages: NiO, 18%; Fe O 50%; ZnO, 32%; produces a rotation of 70 and an attenuation of 0.8 decibel.
Example 3.-The following mixture is ground in the molecular proportions indicated: NiO, 18%; Cr O Fe O 35%; ZnO, 32%. This product, after pressing, is sintered at a temperature of 1200 C. for four hours in an oxygen atmosphere. This material, used in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at the frequency of 9,700 mc./s. a rotation of 45 and anattenuation of 0.05 decibel, when subjected to a longitudinal magnetic field equal to 100 orsted.
Example 4.The following mixture is ground in the molecular proportions indicated: NiO, 17%, Cr O 7%; Fe O 44%; ZnO, 32%. After pressing and sintering at a temperature of 1200 C. for fourhours in an oxygen atmosphere, this material, used-in the form of a circular cylindrical bar 5.5 mm. in diameter and 30 mm. long, produces at a frequency of 9,700 mc./s. a rotation of 30 and a negligible attenuation, when subjected to a longitudinal magnetic field of 100 oersted.
Example 5.-The following mixture in molecular percentage: NiO, 17%; Cr O 7%; Fe O 44%; ZnO, 32%; is ground, then pressed. It is then sintered at 1200" C. for four hours in an oxygen atmosphere. Used in the form of a circular cylindrical bar 6.5 mm. in diameter and 30 mm. long, this material, subjected to a longitudinal magnetic field of 100 oersted, produces a rotation of 90 and an attenuation of 0.3 decibel.
Example 6.'The following mixture in molecular percentage NiO, 13%; Cr O 5%; Fegog, 49%; ZnO, 33% is ground, pressed and sintered at 1250 C. for 4 hours in an oxygen atmosphere. Used in the form of a circular cylindrical bar 5.3 mm. in diameter and 30 mm. long, this material produces a rotation of 50 for a Wave of 9700 mc./s. an attenuation of 0.17 db and an ellipticity of the emerging wave greater than 35 db when subjected to a longitudinal magnetic field of 100 oersted.
Example 7.A composition in molecular percentages of NiO, Cr O 20%; Fe O 30%; Z110, 30% sintered for 4 hours at 1200 C. in an oxygen atmosphere and in the form of a circular rod of 6.5 mm. diameter and 30 mm. long gave, at 9700 mc./s. a rotation of an attenuation of 0.09 db and an ellipticity greater than 35 db when subjected to a longitudinal magnetic field of 100 oersted.
Itrcan be seen from the data given above that the attenuation decreases more rapidly than doesthe rotation of the angle of polarisation within the limits of chromic oxide content indicated and this fact may .be used in the:
selection of the particular composition to be used. The
molecular content of chromic oxide may however be chosen to realise the best compromise the particular device contemplated, since theiinvention is not limited to devices of the particular kind described.
While the principles of the invention have been described above in connection with specific embodiments, and particular modifications thereof, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the in- 'vention.
What we claim is:
1. A body of ferromagnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and presenting a low attenuation to said frequencies, said body being the reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 5 to 20 mol. percent of chromic oxide, from 30 to mol. percent of ferric oxide and the remainder zinc oxide, the sum of the chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of the material, said mixture being compressed and sintered at a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen atmosphere for approximately four hours.
2. A body of ferromagnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and'presenting a low attenuation to said frequencies, said body being the reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 10 to 20 mol. percent of chromic oxide, from 30 to 50 mol. percent of ferric oxide and the remainder zinc oxide, the sum of the chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of'the material, said mixture being compressed and sintered at a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen atmosphere for approximately four hours.
3. A body of ferrogamnetic ceramic material having the properties of a large angle of rotation of the plane of polarisation for energy of microwave frequencies when placed in a longitudinal magnetic field and presenting a low attenuation to said frequencies, said body being the. reaction product of a finely divided mixture of from 13 to 20 mol. percent of nickel oxide, from 5 to 15 mol. percent of chromic oxide, from 35 to 49 mol. percent of ferric oxide and the remainder zinc oxide, the sum of the L chromic oxide and the ferric oxide comprising between 46 and 54 mol. percent of the material, said mixture being compressed and sinteredat a temperature between approximately 1200 C. and approximately 1250 C. in an oxygen a mosphere for approximately four hours:
Referenc s Cited in the file of this patent UNITED STATES PATENTS I 2,579,267 Leverenz Dec. 18, 1951 2,579,978 Snoek et a1. Dec..25, 1951 FOREIGN PATENTS 524,097 Belgium Nov. 30, 1953 1,074,864 France Apr. 7, 1954 1,107,654 France Aug. 10, 1955 OTHER REFERENCES Harvey et al.: R.C.A. Review, vol. XI, No. 3, pages 349, 361, September 1950, pub. by R.C.A., Princeton, NJ.
Claims (1)
1. A BODY OF FERROMAGNETIC CERAMIC MATERIAL HAVING THE PROPERTIES OF A LARGE ANGLE OF ROTATION OF THE PLANE OF POLARISATION FOR ENERGY OF MICROWAVE FREQUENCIES WHEN PLACED IN A LONGITUDINAL MAGNETIC FIELD AND PRESENTING A LOW ATTENUATION TO SAID FREQUENCIES, SAID BODY BEING THE REACTION PRODUCT OF A FINELY DIVIDED MIXTURE OF FROM 13 TO 20 MOL. PERCENT OF NICKEL OXIDE, FROM 5 TO 20 MOL. PERCENT OF CHROMIC OXIDE, FROM 30 TO 50 MOL. PERCENT OF FERRIC OXIDE AND THER REMAINDER ZINC OXIDE, THE SUM OF THE CHROMIC OXIDE AND THE FERRIC OXIDE COMPRISING BETWEEN 46 AND 54 MOL. PERCENT OF THE MATERIAL, SAID MIXTURE BEING COMPRESSED AND SINTERED AT A TEMPERATURE BETWEEN APPROXIMATELY 1200*C. AND APPROXIMATELY 1250*C. IN AN OXYGEN ATMOSPHERE FOR APPROXIMATELY FOUR HOURS.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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FR713711 | 1956-05-02 |
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US2980618A true US2980618A (en) | 1961-04-18 |
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US656421A Expired - Lifetime US2980618A (en) | 1956-05-02 | 1957-05-01 | Ferromagnetic material for gyromagnetic effect |
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US (1) | US2980618A (en) |
BE (1) | BE557138A (en) |
CH (1) | CH377710A (en) |
DE (1) | DE1083742B (en) |
FR (1) | FR1153644A (en) |
GB (1) | GB814506A (en) |
NL (1) | NL101598C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5626789A (en) * | 1991-09-11 | 1997-05-06 | American Research Corp. Of Virginia | Ferrimagnetic core materials for megahertz frequency high flux density transformers and inductors |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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BE524097A (en) * | ||||
US2579267A (en) * | 1947-12-31 | 1951-12-18 | Rca Corp | Material having improved magnetic property |
US2579978A (en) * | 1946-03-27 | 1951-12-25 | Hartford Nat Bank & Trust Co | Soft ferromagnetic material and method of making same |
FR1074864A (en) * | 1952-02-15 | 1954-10-11 | Steatite Res Corp | Square hysteresis loop ferromagnetic compositions |
FR1107654A (en) * | 1954-06-23 | 1956-01-04 | Telecommunications Sa | Low loss magnetic ferroceramic materials |
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0
- NL NL101598D patent/NL101598C/xx active
- BE BE557138D patent/BE557138A/xx unknown
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1956
- 1956-05-02 FR FR1153644D patent/FR1153644A/en not_active Expired
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1957
- 1957-04-26 GB GB13367/57A patent/GB814506A/en not_active Expired
- 1957-04-30 DE DEC14756A patent/DE1083742B/en active Pending
- 1957-05-01 US US656421A patent/US2980618A/en not_active Expired - Lifetime
- 1957-05-02 CH CH4566857A patent/CH377710A/en unknown
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE524097A (en) * | ||||
US2579978A (en) * | 1946-03-27 | 1951-12-25 | Hartford Nat Bank & Trust Co | Soft ferromagnetic material and method of making same |
US2579267A (en) * | 1947-12-31 | 1951-12-18 | Rca Corp | Material having improved magnetic property |
FR1074864A (en) * | 1952-02-15 | 1954-10-11 | Steatite Res Corp | Square hysteresis loop ferromagnetic compositions |
FR1107654A (en) * | 1954-06-23 | 1956-01-04 | Telecommunications Sa | Low loss magnetic ferroceramic materials |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5626789A (en) * | 1991-09-11 | 1997-05-06 | American Research Corp. Of Virginia | Ferrimagnetic core materials for megahertz frequency high flux density transformers and inductors |
US6433299B1 (en) | 1991-09-11 | 2002-08-13 | American Research Corporation Of Virginia | Monolithic magnetic modules for integrated planar magnetic circuitry and process for manufacturing same |
Also Published As
Publication number | Publication date |
---|---|
BE557138A (en) | |
NL101598C (en) | |
GB814506A (en) | 1959-06-03 |
DE1083742B (en) | 1960-06-15 |
CH377710A (en) | 1964-05-15 |
FR1153644A (en) | 1958-03-19 |
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