GB2243152A - Magnetic material for microwave and millimeter wave frequencies - Google Patents
Magnetic material for microwave and millimeter wave frequencies Download PDFInfo
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- GB2243152A GB2243152A GB9106859A GB9106859A GB2243152A GB 2243152 A GB2243152 A GB 2243152A GB 9106859 A GB9106859 A GB 9106859A GB 9106859 A GB9106859 A GB 9106859A GB 2243152 A GB2243152 A GB 2243152A
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- 239000000696 magnetic material Substances 0.000 title claims abstract description 23
- 239000000203 mixture Substances 0.000 claims abstract description 23
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 22
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 12
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 12
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 claims abstract description 12
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229910000428 cobalt oxide Inorganic materials 0.000 claims abstract description 10
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 9
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 9
- 229910052681 coesite Inorganic materials 0.000 claims abstract description 6
- 229910052906 cristobalite Inorganic materials 0.000 claims abstract description 6
- CJNBYAVZURUTKZ-UHFFFAOYSA-N hafnium(IV) oxide Inorganic materials O=[Hf]=O CJNBYAVZURUTKZ-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 6
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 6
- 229910052682 stishovite Inorganic materials 0.000 claims abstract description 6
- 229910052905 tridymite Inorganic materials 0.000 claims abstract description 6
- 239000000654 additive Substances 0.000 claims abstract description 3
- 229910052751 metal Inorganic materials 0.000 claims abstract description 3
- 239000002184 metal Substances 0.000 claims abstract description 3
- 230000005291 magnetic effect Effects 0.000 description 23
- 230000004907 flux Effects 0.000 description 14
- 230000005415 magnetization Effects 0.000 description 12
- 229910000859 α-Fe Inorganic materials 0.000 description 10
- 230000005350 ferromagnetic resonance Effects 0.000 description 7
- -1 as specimens No. 3 Chemical compound 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical class [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- 229910001928 zirconium oxide Inorganic materials 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Chemical compound O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 description 2
- 238000010587 phase diagram Methods 0.000 description 2
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910001429 cobalt ion Inorganic materials 0.000 description 1
- XLJKHNWPARRRJB-UHFFFAOYSA-N cobalt(2+) Chemical compound [Co+2] XLJKHNWPARRRJB-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011369 resultant mixture Substances 0.000 description 1
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
- C04B35/2608—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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/34—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites
- H01F1/342—Oxides
- H01F1/344—Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4
- H01F1/346—[(TO4) 3] with T= Si, Al, Fe, Ga
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/32—Non-reciprocal transmission devices
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Dispersion Chemistry (AREA)
- Power Engineering (AREA)
- Magnetic Ceramics (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Soft Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
Abstract
A magnetic material for microwave and millimeter wave frequencies consists essentially of a main component having a composition represented by the general formula: (Y1-xGdx)w(FE1-y-zAly Mnz)8-wO12 wherein x, y, z and w take a value within the following respective ranges: 0 </= x </= 0.35, 0 </= y </= 0.16, 0.01 </= z </= 0.04, and 3.02 </= w </= 3.06, and additives composed of cobalt oxide and at least one tetravalent metal oxide selected from the group consisting of SiO2, TiO2, GeO2, SnO2, HfO2 and ZrO2, a content of cobalt oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of CoO, a content of the above at least one tetravalent metal oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of MeO2 (Me represents at least one tetravalent metal).
Description
MAGNETIC MATERIAL FOR MICROWAVE
AND MILLIMETER WAVE FREQUENCIES
The present invention relates to a magnetic material for microwave and millimeter wave frequencies and, more particularly, a magnetic composition for high frequency circuit elements designed for use in microwave and millimeter wave frequency ranges.
As a magnetic material for high frequencies, there have been used those such as Mn-Mg ferrites, Ni-Zn ferrites, lithium ferrites and YIG ferrites as they possess a high saturation magnetization (4xmas) ranging from 500 to 4000 gauss.
Among them, YIG ferrites are applicable to the production of highly stable circuit elements such as isolators and circulators. Because, as disclosed in U.S. patent 3,132,105, the saturation magnetization (4rums) and the temperature coefficient of 4rums (a) may be controlled by replacing a part of the ingredients of Y3Fe5012 with Gd and
Al, thus making it possible to select a magnetic material with an optimum value of the saturation magnetization for operating frequencies. In addition, a combined use of such a YIG ferrite with a permanent magnet makes it possible to compensate the temperature characteristics of the magnet.
U.S. patent 3,419,496 teaches that YIG ferrite possesses a low volume specific resistance (s) of 7.0 x 108 n. cm, but its volume specific resistance (P) can be improved to 4.9 x 10 fl.cm by incorporation of MnO2 into Y3Fe5012.
Further, Japanese patent publication No. 60-55970 teaches that the YIG ferrites composed of 38.63 to 39.45 mole % of Y203 and 60.55 to 61.37 mole % of Fe2O3 possess the minimum ferromagnetic resonance line width (H) of 16 Oersted (Oe).
However, the YIG ferrites of the prior art have such a disadvantage that values of the ferromagnetic resonance line width (H) and dielectric loss tangent (tan Ee) considerably varies with a very small deviation of the composition, thus making it impossible to put them into practical applications. Also, the greater the residual magnetic flux density (Br) the greater is the dielectric loss tangent, so that the ferrites cannot be applied to production of elements for phase converters which are required to have a high residual magnetic flux density.
It is therefore an object of the present invention to provide a magnetic material for microwave and millimeter wave frequencies with a very small value of the ferromagnetic resonance line width (at), a high value of the residual magnetic flux density (Br) and a small value of the dielectric loss tangent (tan Sue).
The above object is attained by incorporating a certain amount of cobalt oxide and at least one tetravalent metal oxide selected from the group consisting of SiO2, TiO2, GeO2, SnO2, HfO2 and Zro2, into a basic composition expressed by the general formula: YwFe8 w 12 with w ranging from 3.02 to 3.06, while replacing a part of
Fe in the basic composition, YwFe8-wO12, with Mn.
In the above basic composition, a part of Y in YwFe 8-wO12 may be replaced with Gd to control the temperature coefficient of saturation magnetization (a) to a desired value as occasion demands. Also, a part of Fe in YwFe w 12 may be replaced with Al to control 4 amps to a desired value as occasion demands.
According to the present invention, there is provided a magnetic material for microwave and millimeter wave frequencies consisting essentially of a main component having a composition represented by the general formula:
(Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12 wherein x, y, z and w take a value within the following respective ranges: 0 s x s 0.35, 0 5 y s 0.16, 0.01 5 z 5 0.04, and 3.02 s w s 3.06, and additives composed of cobalt oxide and at least one tetravalent metal oxide selected from the group consisting of SiO2, TiO2, GeO2, SnO2, HfO2 and
ZrO2, a content of cobalt oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of CoO, a content of said at least one tetravalent metal oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of MeO2 (Me represents at least one tetravalent metal).
The magnetic material according to the present invention has a composition falling within a quadrangular area defined by points A, B, C and D in Fig. 1, the sets of molar fractions of the components at the above points being as follows:
x Y
A 0.0 0.00
B 0.0 0.16
C 0.35 0.16
D 0.35 0.00
A magnetic material according to the present invention possesses a sufficiently small ferromagnetic resonance line width (to), small dielectric loss tangent (tan eye), and large residual magnetic flux density (Br). In addition, the above magnetic composition possesses a high curie temperature. Accordingly, it is possible to obtain a magnetic material fitted to circuit elements for microwave and millimeter wave frequencies, such as latching type phase convertors, highly stable isolators, circulators and the like.
Since the present invention makes it possible to obtain a magnetic material with a desired value of the saturation magnetization (4#Ms) ranging from 320 to 1750 gauss, it is possible to select a magnetic material with a value of the saturation magnetization (4rMs) most pertinent for the operating frequency of the circuit elements to be produced.
In addition, the magnetic material of the present invention may have a desired value of the temperature coefficient of 4rms (a) ranging from -780 to -2550 ppm/ C.
Thus, the combination of the magnetic material with a permanent magnet makes it possible to compensate the temperature characteristics of the magnet.
Further, the magnetic material of the present invention is high in the residual magnetic flux density (Br), but small in the ferromagnetic resonance line width (AH) and in the dielectric loss tangent (tan 6e), thus making it possible to obtain a magnetic material fitted for production of latching type phase converters, high precision isolators and circulators, and the like.
The above and other objects, features and advantages of the present invention will be further apparent from the following explanation with reference to the examples and accompanying drawings, in which:
Fig. 1 is a phase diagram of a magnetic material of a (Y1, Gd ) (Fel Al Mn )8-P12 system, showing the compositional area of the magnetic material for microwave and millimeter wave frequencies according to the present invention; and
Fig. 2 is a graph showing the effects of a value of w in the system (Y1-xGdx)x(Fe-1-y-zAlyMnz)8-wO12 on the dielectric loss and the residual magnetic flux density of the magnetic material. In this figure, the dielectric loss is given by a value of a natural logarithm of tan 6, i.e., log tan 6.
EXAMPLE
Highly purified Y203, Fe2O3, Gd2O3, 2 3 2 Cho 304 and ZrO2 were used as raw materials. These materials were weighed in proportions shown in Table 1, and milled by the wet process for 16 hours with a ball mill. After drying, the resultant mixture was calcined at 1050 C for 2 hours, crushed and then ground along with an organic binder by the wet process for 16 hours with a ball mill. After drying, the resultant powder was passed through a 50 mesh sieve to prepare granulated powder. The resultant powder was compacted to form square rods with size of 3 mm x 3 mm x 20 mm and rings with size of 36 mm (outer diameter) x 24 mm (inner diameter0 x 6 mm (thickness0 at a pressure of 2000
Kg/cm. The resultant green compacts were fired at 1460 to 1490 C for 8 hours.Square rods were machined to prepare spherical specimens with a diameter of 1.3 mm and columnar specimens with a diameter of 1.3 mm and a length of 16 mm.
For each spherical specimen, measurements were made on the saturation magnetization (4rums), temperature coefficient of saturation magnetization (a), ferromagnetic resonance line width (AH) and Curie temperature (Tc).
The saturation magnetization (4rms), temperature coefficient of saturation magnetization (a) and Curie temperature (Tc) were measured with a vibrating sample magnetometer, while the ferromagnetic resonance line width (AH) at 10 GHz was measured with a TE106 mode cavity resonator by a method defined by Japan Industrial Standard C-2561.
For each columnar specimen, measurements were made on dielectric loss tangent (tan 6e) at 10 GHz with a TM101 mode cavity resonator by the perturbation method defined in
Japan Industrial Standard C-2561.
For each ring specimen with bifilar toroidal coils, measurements were made on residual magnetic flux density (Br) at 100 Hz and coercive force (Hc) at 100 Hz by drawing B-H (magnetic flux density to applied magnetic field) hysteresis curves.
Results are shown in Table 2 and Fig. 2.
TABLE 1
No. (Y1-xGdx)wY(Fe1-y-zAlyMnz)8-wO12 Content Content
x Y z w of CoO of ZrO2
(mol%) (mol%)
1 0 0 0.02 3.04 0.1 0.1
2* " 0,08 " " 0 0
3* " " " " 0.01 0.01
4 " " " " 0.1 0.1
5* " " " " 0.5 0.5
6 " 0.16 " " 0.1 0.1
7* .. 0.20
8 0.20 0 0.02 3.04 0.1 0.1
9* " 0.08 " " 0 0 10* " " " " 0.01 0.01 11 " " " " 0.1 0.1 12* " " " " 0.5 0.5 13 " 0.16 " " 0.1 0.1 14* " 0.20 " " " " 15 0.35 0 0.02 3.04 0.1 0.1 16* " 0.08 " " 0 0 17* " " " " 0.01 0.01 18 " " " " 0.1 0.1 19* " " " " 0.5 0.5 20 " 0.16 " It 0.1 0.1 21* " 0.20
TABLE 1 (contd.)
No. (Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12 Content Content
x Y z w of CoO of ZrO2
(mol%) (mol%) 22* 0.42 0 0.02 3.04 0.1 0.1 23* " 0.08 " " " " 24* " 0.16 " " " " 25* " 0.20 ..
26* 0 0.08 0 3.04 0.1 0.1 27 " " 0.01 " " " 28 " " 0.02 " " " 29 " " 0.04 " " " 30* " " 0.06 " " " 31* 0.20 0.08 0 3.04 0.1 0.1 32 " " 0.01 " " " 33 " " 0.02 " " " 34 " " 0.04 " " " 35* " " 0.06 " " " 36* 0.35 0.08 0 3.04 0.1 0.1 37 " " 0.01 " " " 38 " " 0.02 " " " 39 " " 0.04 " " " 40* " " 0.06 " " "
TABLE 1 (contd.)
No. (Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12 Content Content
x Y z w of CoO of ZrO2
(mol%) (mol%) 41* 0 0.08 0.02 3.00 0.1 0.1 42 " " " 3.02 " " 43 " " " 3.04 " " 44 " " " 3.06 " " 45* 1 1 3.08 " " 46* 0.20 0.08 0.02 3.00 0.1 0.1 47 " " " 3.02 " " 48 " " " 3.04 " " 49 " " " 3.06 " " 50* " " " 3.08 " " 51* 0.35 0.08 0.02 3.00 0.1 0.1 52 " " " 3.02 " " 53 " " " 3.04 " " 54 " " " 3.06 " " 55* 1 " " It 3.08 It It
TABLE 2 No. 4#ms a aH tan 5 Br Hc Tc (gauss) (ppm/ C) (Oe) (x10- @ (gauss) (Oe) ( C) 1 1750 -2480 25 8.2 1410 0.64 280
2* 1220 -2520 29 7.9 1005 0.72 215
3* " -2510 27 " 990 0.71 210 4 " II 15 7.7 960 " " II 5* 1190 -2470 51 9.5 750 0.80
6 750 -2550 25 8.0 580 0.70 180
7* 330 -2640 38 12.7 260 1.10 90
8 1470 -2090 25 6.5 1220 0.68 280
9* 900 -2010 33 6.3 755 0.71 235 10* " -2000 32 6.2 750 0.70 230 11 It -1990 17 6.0 730 0.69 12* 880 -1940 61 6.8 580 0.91 13 450 -2240 30 8.4 380 0.80 190 14* 280 -2390 39 9.5 220 0.83 110 15 1120 -740 32 9.9 910 0.72 280 16* 700 -910 42 13.5 580 0.82 220 17* " -900 40 13.4 II 0.80 18 690 -890 20 12.1 550 0.76 19* 670 -820 68 14.9 440 0.91 230 20 320 -1080 36 13.6 230 0.81 170 21* 170 -1270 49 14.0 140 0.72 100
TABLE 2(contd.) No. 4#ms α #H tan # Br Hc Tc (gauss) (ppm/ C) (Oe) (x10-5) (guass) (Oe) ( C) 22* 970 -630 74 12.5 810 0.89 260 23* 570 -640 91 13.2 410 0.96 210 24* 210 -650 93 14.6 90 1.10 160 25* 120 -850 97 15.0 70 1.02 85 26* 1190 -2430 45 7.8 970 0.66 210 27 II -2500 34 8.0 980 0.72 220 28 1220 -2510 15 7.7 960 0.71 210 29 1180 -2330 28 9.2 940 0.69 30* 1160 -2290 39 13.6 960 0.91 31* 890 -2070 62 6.1 740 0.75 230 32 II -1970 40 4.9 " 0.68 240 33 990 -1990 17 6.0 730 0.69 230 34 860 -1870 34 9.4 720 0.73 35* 870 -1910 77 21.6 II 0.81 220 36* 690 -870 68 12.4 530 0.77 220 37 700 " 59 11.5 540 0.81 210 38 -690 -890 20 12.1 550 0.76 220 39 " -860 44 19.4 520 0.78 210 40* I -840 82 29.6 500 0.88
TABLE 2(contd.) No. 4#ms α #H tan # Br Hc Tc (gauss) (ppm/ C) (Oe) (x10-5) (guass) (Oe) ( C) 41* 1240 -2510 28 1173.5 910 0.85 220 42 " -2440 26 20.1 980 0.71 43 1220 -2510 15 7.7 960 " 210 44 1210 -2410 26 7.6 920 0.63 45* 1160 -2290 39 13.6 960 0.91 46* 910 -1870 30 1324.9 690 0.73 240 47 890 -1910 25 18.8 710 0.70 220 48 900 -1990 17 6.0 730 0.69 230 49 880 -1870 27 5.8 690 0.68 240 50* 890 -1890 39 6.5 540 0.66 220 51* 720 -880 35 1226.1 500 0.77 220 52 690 -890 31 16.6 540 0.74 53 II " 20 12.1 550 0.76 220 54 680 -780 32 11.9 470 0.75 210 55* 670 -790 46 14.8 400 0.77
In the table, the specimens with an asterisk (*) are those beyond the scope of the present invention, while other specimens are those falling within the scope of the present invention defined in the phase diagram of Fig. 1.
The compositions of the above specimens are plotted in Fig.
1 with numerals corresponding to that of the specimen numbers.
The reasons why the magnetic material of the present invention has been limited to those having a composition defined as above are apparent from the following description.
From the data for specimens No. 1 to 25, it will be seen that partial substitution of Al Fe in YwFe 8-w0 12 makes it possible to control the saturation magnetization (4rms) 4rms to a desired value. However, compositions containing Al exceeding 0.16, like as specimens No. 7, 14, 21 and 25, are lowered in the residual magnetic flux density (Br) and the Curie temperature (Tc). Thusr the molar fraction of Al in (Fe Al Mn ), i.e., y, has been limited
l-y-z y z to a value of not more than 0.16.
Also, it will be seen that partial substitution of
Gd for Y in YwFe 8 -wO 1 2 makes it possible to control a temperature coefficient of saturation magnetization (a).
However, compositions containing Gd exceeding 0.35, like as specimens No. 22, 23, 24 and 25, possess large magnetic resonance line width (at). Thus, the molar fraction of Gd in (Y1 XGdx), i.e., x, has been limited to a value of not more than 0.35.
Both cobalt oxide and zirconium oxides are incorporated into YwFe8 w 12 to minimize the a value of #H.
However, compositions containing less than 0.05 mole % CoO and less than 0.05 mole % ZrO2, like as specimens No. 3, 10 and 17, are scarcely improved in aH, as compared with specimens No. 2, 9 and 16 each of which contains no CoO and
ZrO. On the other hand, compositions containing more than 0.2 mole % CoO and more than 0.05 mole % ZrO2, like as specimens No. 5, 12 and 1 9, possess large AH but small Br.
Thus, each added amount of CoO and ZrO has been limited to a value within the range of 0.05 to 0.2 mole %.
Zirconium oxide has been incorporated into (Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12 together with cobalt oxide to compensate the valency of diva lent cobalt ions by tetravalent zirconium ions so that both cobalt and zirconium ions are incorporated into the ( Fe Al Mn ) site in the
1-y-z y z form of combined trivalent ions, (Co1/2Zr1/2) 3, without causing charged defects. Similar effects are obtained by using any one of tetravalent metal oxides such as SiO2,
TiO2, GeO2, SnO2 and HfO2, in stead of ZrO2.Thus, cobalt oxide may be incorporated into the (Yl-xGdx)w( Fe1-y-zAlyMnz)8-wO12 system together with at least one tetravalent metal oxide selected from the group consisting of SiO2, TiO2, GeO2, SnO2, HfO2 and ZrO2
From the data for specimens No. 26 to 40, it will be seen that partial substitution of Mn for Fe in Y Fe 0
w 8-w 12 containing small amounts of cobalt and zirconium oxides reduces a value of magnetic resonance line width (AH).
However, compositions containing less than 1 mole % Mn, like as specimens No. 26, 31 and 36, are not so improved in the magnetic resonance line width (#H). Further, compositions containing than 4 mole % Mn, like as specimens No. 30, 35 and 40, possess large magnetic resonance line width (#H).
Thus, the molar fraction of Mn in (Fe1 y zAlyMnz), i.e., z, has been limited to a value within the range of 0.01 to 0.04.
Data for specimens No. 41-45, 46-50 and 51-55 in
Table 1 show effects of w in (Y1-x-Gdx)w(Fe1-y-zAlyMnz)8-wO12 on the residual magnetic flux density (Br) dielectric loss tangent (tan a). Compositions with a value of w less than 3.02, like as specimens No. 41, 46 and 51, possess considerably large dielectric loss tangent (tan 6). In contrast therewith, compositions containing (Y1 XGdx) greater than the stoichiometric compositions are considerably improved in the residual magnetic flux density (Br) and dielectric loss tangent (tan 6). However, compositions with w exceeding 3.06, like as specimens No.45, 50 and 55, are large in the magnetic resonance line width (#H) but small in the residual magnetic flux density (Br). Thus, the molar ratio of the the Y site component, i.e., w has been limited to a value ranging from 3.02 to 3.06.
Fig. 2 shows variations of the dielectric loss and the residual magnetic flux density (Br) as a function of a value of w in the system (Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12.
The data on dielectric loss are plotted by taking the common logarithm of dielectric loss tangent (log tan #e).
From this figure, it will be seen that the magnetic composition are large in residual magnetic flux density (Br) but small in dielectric loss tangent (6e) only when w in (Y1-xGdx)w(Fe1-y-z-Aly-Mnz)8-wO12 takes a value within the range of from 3.02 to 3.06.
Claims (2)
1. A magnetic material for microwave and millimeter wave frequencies consisting essentially of a main component having a composition represented by the general formula:
(Y1-xGdx)w(Fe1-y-zAlyMnz)8-wO12 wherein x, y, z and w take a value within the following respective ranges: 0 s x s 0.35, 0 s y s 0.16, 0.01 s z 5 0.04, and 3.02 s w 5 3.06, and additives composed of cobalt oxide and at least one tetravalent metal oxide selected from the group consisting of SiO2, TiO2, GeO2, SnO2, HfO2 and
ZrO2, a content of cobalt oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of CoO, a content of said at least one tetravalent metal oxide being not less than 0.05 mole % but not more than 0.2 mole % in terms of MeO2 (Me represents at least one tetravalent metal).
2. A magnetic material substantially as exemplified herein.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2090747A JP2504273B2 (en) | 1990-04-04 | 1990-04-04 | Microwave / millimeter wave magnetic composition |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9106859D0 GB9106859D0 (en) | 1991-05-22 |
| GB2243152A true GB2243152A (en) | 1991-10-23 |
| GB2243152B GB2243152B (en) | 1993-10-20 |
Family
ID=14007189
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9106859A Expired - Lifetime GB2243152B (en) | 1990-04-04 | 1991-04-02 | Magnetic material for microwave and millimeter wave frequencies |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2504273B2 (en) |
| GB (1) | GB2243152B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0743660A1 (en) * | 1995-05-10 | 1996-11-20 | Murata Manufacturing Co., Ltd. | Magnetostatic wave device and material for the same |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4586215B2 (en) * | 1998-04-14 | 2010-11-24 | Ｔｄｋ株式会社 | Method for controlling intermodulation product of nonreciprocal circuit element, ferrimagnetic material, and nonreciprocal circuit element using the same |
| US6933799B1 (en) | 1998-04-14 | 2005-08-23 | Tdk Corporation | Method of controlling intermodulation distortion of non-reciprocal device |
| JP2007036108A (en) * | 2005-07-29 | 2007-02-08 | Tdk Corp | Ceramic material for non reciprocal circuit element of, and its manufacturing method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56162715A (en) * | 1980-05-20 | 1981-12-14 | Matsushita Electric Ind Co Ltd | Magnetic and optical element |
| JPS627631A (en) * | 1985-06-29 | 1987-01-14 | Toshiba Corp | Magneto-optical element |
-
1990
- 1990-04-04 JP JP2090747A patent/JP2504273B2/en not_active Expired - Lifetime
-
1991
- 1991-04-02 GB GB9106859A patent/GB2243152B/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0743660A1 (en) * | 1995-05-10 | 1996-11-20 | Murata Manufacturing Co., Ltd. | Magnetostatic wave device and material for the same |
| US5879824A (en) * | 1995-05-10 | 1999-03-09 | Murata Manufacturing Co., Ltd. | Magnetostatic wave device and material for the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2504273B2 (en) | 1996-06-05 |
| JPH03288406A (en) | 1991-12-18 |
| GB9106859D0 (en) | 1991-05-22 |
| GB2243152B (en) | 1993-10-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Expiry date: 20110401 |