GB2413127A - Microwave dielectric ceramic - Google Patents

Microwave dielectric ceramic Download PDF

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GB2413127A
GB2413127A GB0507459A GB0507459A GB2413127A GB 2413127 A GB2413127 A GB 2413127A GB 0507459 A GB0507459 A GB 0507459A GB 0507459 A GB0507459 A GB 0507459A GB 2413127 A GB2413127 A GB 2413127A
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catio3
doped
dielectric material
composition
consisting essentially
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GB2413127B (en
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David Martin Iddles
Duncan Muir
Timothy James Price
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Filtronic Comtek PLC
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Filtronic Comtek PLC
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Priority claimed from GB0501259A external-priority patent/GB0501259D0/en
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Priority to GB0713582A priority Critical patent/GB2440047B/en
Priority to GB0713583A priority patent/GB2440048B/en
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Abstract

A dielectric ceramic material consisting essentially of a composition of Formula 1 <CHE>xATiO3(1-x) Re(Z0.5Ti0.5)O3```(1)</CHE> wherein A may be selected from the group consisting of: Ca, Sr, Mg, Ba and mixtures thereof; Re may be selected from a group consisting of La, Nd or Sm and mixtures thereof; Z may be selected from mixtures of Zn, Mg, Co, Cu, Ni and mixtures thereof; and wherein x is a positive number less than 1. The dielectric ceramic material may further comprise a small amount of dopant selected from the group consisting of MnO2, CeO2, Al2O5, Fe2O3, Nb2O5, Ta2O5, Dy2O3, WO3, Ga2O3, Y2O3, SnO2 and mixtures therof. Preferably 0.05 to 5% dopant is present.

Description

MICROWAVE DIELECTRIC CERAMIC
This invention relates to a dielectric ceramic material and also to a dielectric resonator comprising the novel ceramic material, the resonator being particularly useful for microwave application.
US-A-4670409 discloses a dielectric ceramic material comprising lanthanum magnesium titanate having a perovskite structure.
According to the present invention there is provided a dielectric ceramic material consisting essentially of a composition of Formula I xATiO3 (1-x) Re(Z0 5Tio 5)O3 (1).. . 0 wherein A may be selected from the group consisting of: Ca, Sr, Mg, Ba and mixtures thereof; Re may be selected from a group consisting of La, Nd or Sm and mixtures thereof; Z may be selected from mixtures of Zn, Mg, Co, Cu. Ni and mixtures thereof; and.. :.
wherein x is a positive number less than 1. ....
Materials in accordance with this invention find application in microwave based filters (single and multimode). Preferred materials may be prepared which allow changes to relative permittivity Er and TCf values while retaining Q values >10,000 at 2 GHz suitable for their intended applications.
Preferred materials in accordance with this invention possess high relative permittivity Er values in comparison to known materials with equivalent Q values.
Materials in accordance with the present invention may further comprise a small amount of a dopant preferably from 0.05 to 5%, selected from the group consisting of MnO2, CeO2 Al2O3, Fe2O3 Nb2O5, Ta2O5, Dy2O3, WO3, Ga2O3, Y2O3, SnO2 and mixtures thereof.
Rare earth elements selected from Eu, Gd, Dy, Pr and mixtures thereof may also be used as dopants. These compounds may be added as oxides.
Materials in accordance with this invention possess further advantages in relation to lanthanum containing materials disclosed in the prior art, for example US-A-4670409, s because rare earth oxides, particularly lanthanum oxides undergo exothermic reactions with water so that lanthanum based materials can be difficult to process on a production scale.
Preferred materials in accordance with this invention include compounds consisting essentially of Formulae (2) to (7) CaTiO3 - La(Zn0 sTio 5) O3 (2) 0 CaTiO3 - La(MgOsTi05)O3 (3) .
CaTiO3 - Nd(ZnO 5Tio 5)O3 (4) CaTiO3 - Nd(Mgo sTio 5)O3 CaTiO3 Sm(Zn0 sTio 5)O3 (6) ...
CaTiO3 - Sm(MgO 5Tio 5)O3 ( ) A further preferred embodiment of the invention includes compounds consisting essentially of.
Formula 8 a Nd((zncMg'-c)bTi'-b)o3 + (1-a) CaTiO3 (8) wherein 0.4 < a < 0.6 0.4 < b 0.6 0< c < 0.2 A preferred composition consists essentially of Formula 9 0.5 Nd((ZnO45Mg005)Ti05)o3 + 0.5 CaTiO This composition may be referred to NZMT-CT 2s Examples of particularly preferred compositions have the Formulae 10- 26 0.5 Nd((Zn045Mg005)Ti05)O3 + 0.5 CaTiO3 + 0.1 wt% CeO2 (10) 0.5 Nd((Zn045Mg00)Ti049Nb00)O3 + 0 5 CaTiO3 + 0.5 wt% CeO2 (11) 0 5 (Nd099ceool)((zno45Mgoo5)Tio5)o3 + 0.5 CaTiO3 (12) 0 5 Nd((Zno4sMgoo5)Tio49Nbo()l)O3 + 0 5 CaTiO3 (13) 0 5 Nd((Zn<)45Mg005)Ti049Ta00l)O3 + 0 5 CaTiO3 (14) 0 5 Nd((Zn)44AloolMgoo5)Tio5)O3 + 0.5 CaTiO3 (15) 0.55 CaliO3 + 0.45 La(Zn0395Ti0395AI02l)O3doped with 0.005 to 5 wt% CeO2 (16) 0.55 CaTiO3 + 0.45 La(Zn0395Ti0395AI02l)O3doped with 0.005 to 5 wt% Ta2O5 (17) 0 0.55 CaTiO3 + 0.45 La(ZnO 395Tio 395Alo 21) 3 doped with 0.005 to 5 wt% Nb2O5 (18) 0.55 CaTiO3 + 0.45 La(Zn0395Ti0395AI02,)O3doped with 0.005 to 5 wt% CoO (19) 0.55 (Cal xSrx)TiO3 + 0.45 La(Zn0395Ti0395AI02)O3doped with 0.005 to 5 wt% CeO2 . where x is between 0.001 and 0.10. (20) .. -
0.55 (Ca xSrx)TiO3 + 0.45 La(Zn0395Ti0395Al02)O3doped with 0.005 to 5 wt% Ta2O where x is between 0.001 and 0.10. (21) 0.55 (Ca xSrx)TiO3 + 0.45 La(ZnO 395Tio 395AIo 2)O3 doped with 0.005 to 5 wt% Nb2O5. where x is between 0.001 and 0.10. (22) .... ë -.
0.55 (Ca xSrx)TiO3 + 0.45 La(ZnO 395Tio 395Alo 2)O3 doped with 0.005 to 5 wt% CoO where x is between 0.001 and 0.10. (23) A CaTiO3 + (1-A) Nd((Zn045Mg005)xTi05Aly))o3 doped with 0.005 to 5 wt% CeO2 Where A is between 0.35 and 0.65.
x is between 0.15 and 0.49. y is between 0.01 and 0.35 (24) A CaTiO3 + (1A) Nd((Zn045Mg005)xTi05Aly))o3 doped with 0.005 to 5 wt% Ta2O5 Where A is between 0.35 and 0.65.
2s x is between 0.15 and 0.49. y is between 0.01 and 0.35 (25) A CaTiO3 + (1 -A) Nd((ZnO 45Mgo 05)xTio 5Aly))03 doped with 0.005 to 5 wt% Nb2O5 Where A is between 0.35 and 0.65.
x is between 0.15 and 0.49. y is between 0.01 and 0.35 (26) CeO2 may be used as a dopant or as a substituent for Nd2O3. Dopant quantities are between 0.05 and 1 wt% as an excess or 0.01 and 0.1 moles as a substituent.
Nb2O5 & Ta205 or a combination of the two may be used as dopants to substituent for TiO2 in amounts between 0.01 and 0.1 moles.
Al203 & Ga2O3 or a combination of the two may be used as dopants to substituent for ZnO or MgO in amounts between 0.01 and 0.1 moles.
s CeO2, Nb2O5, Ta2O5 or Al2O3 & Ga2O3 may be used in any combination together either as substituents or excess dopants in amounts between 0.01 and 0.1 moles.
A further preferred embodiment of the invention includes compounds consisting essentially of Formula 17 a La(ZncMgTibAle(Nb or Ta)f)O3 + (1a) (CagSr g)TiO3 (27) wherein. . 0.4 < a < 0.6 .
0 < b < 0.5.
0< c < 0.5:' 0 < d < 0.5:.' 0 < e < 0.8 0< f < 0.2 'a'' 0< g < 1.0 ' ' ... :
whereb+c+d+e+f= 1 To all the above may also be added CeO2 in amounts up to 2 wt%.
Examples of particularly preferred compositions have the formulae 28-34 Base composition: 0.5 La(ZnO 5Tio 5)O3 + 0.5 CaTiO3 (28) Doped compositions include: 0 5 La((ZnO 475Alo 05)Tio 475)O3 + 0.5 CaTiO3 to 0.5 La(ZnO IAlo RTio 1) 3 + 0.5 CaTiO3 (29) Exemplified composition include: 0 5 La((Zn0 47sAIo os)Tio 475)O3 + 0.5 CaTiO3 to 0.5 La(Zrb SAID 8Tio JO + 0.5 CaTiO3 plus 0.1 to 0.5 wt% CeO2 (30) 0 5 (La099Ce0o')(zno45Alo Tio45)O3 + 0.5 CaTiO3 (31) 0.5 La(Zn045Al005Ti045)O3 + 0.5 CaTiO3 doped in amounts up to 0.1 moles Nb2O5 (32) 0.5 La(Zn045Al005Ti045)O3 - 0.5 CaTiO3 doped in amounts up to 0.1 moles Ta2O5 (33) 0.5 La(Zn045AI005Ti045)O3 + 0.5 CaTiO3 doped in amounts up to I mole SrO for CaO (34) 0 In further embodiments Zn may be wholly or partially replaced by Mg.
The electrical properties for these ceramics can be summarised as follows: .
crag - 58...
Q (.5 GHz) 6k-16k.
TCf (variable through composition) -30 to +50 MK-' ....
Further preferred compositions have the formula (35) optionally co-doped with a manganese . compound equivalent to up to 1% MnO2 (35) . a Nd(ZncMgdTibAle(Nb or Ta or Ce)f)03 + (1-a) (CagSr' g)TiO3 wherein: 0. 4<a<0.6 0<b<0.5 o<c<0.5 0<d<0.5 0<e<0.8 0<f<0.2 0<g<1.0 Particularly preferred components have the Formulae (36)-(39) optionally (36)-(39) codoped with a manganese compound equivalent to 1% MnO2.
032 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3. (36) 032 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3 plus 0.005 to 5 wt% CeO2. (37) 0.32 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3 plus 0.005 to 5 wt% Nb2Os. (38) 0.32 Nd(ZnO45MgOO5TiO')03 + 0.1 NdAIO' + 0.58 CaTiO3 plus 0.005 to 5 wt% Ta2O5. (39) Compositions of the present invention may be manufactured by mixing the appropriate oxides, carbonates, hydroxides or other compounds in the above mentioned proportions, pulverising the mixture using a wet or dry method, calcining the mixture at a temperature of I l 00 C to s 1400 C for 1 to 4 hours, shaping the calcined mixture into an optional form and sintering the shaped body at a temperature of l 400 C to l 700 C.
Percentages and other amounts referred to in this specification are by weight unless indicated otherwise. Percentages and other proportions are selected to total 100%.
The invention is further described by means of example but not in any limitative sense.
lo Example l....
All initial starting powders were of purity > 99%. The raw materials were weighed in the.
appropriate quantities to form the compositions required. Deionised water or iso propan-2-ol was added to the weighed batches which were subsequently ball milled with magnesia ' stabilised zirconia milling media for 16 hours. Alternatively, the materials were attrition. . milled for 2 hours with yttria stabilised zirconia media. Subsequently, the raw material batches A. were dried at 80 C and sieved through a 250m nylon mesh. The dried powder was calcined (preform the required phase) at temperatures in the interval 11 00 C to 1400 C for 1 to 16 hours. The as-calcined powders were re-milled with 2 wt% PEG binder (MW 10000) for 8 hours, dried and sieved. Standard test samples of 1 Og weight were uniaxially pressed in a 20 mm hardened stainless steel die using a pressure of 30 MPa. Sintering of the pellets was performed between 1350 and 1700 C for 1 to 48 hours under either an air or oxygen atmosphere. Due to the high sintering temperatures employed, precautions were undertaken to minimise zinc oxide volatilisation at temperature. All samples were of density > 95% theoretical density using the Archimedes immersion technique.
2s The electrical properties were tested on the sintered components. Microwave dieleckic properties were measured in reflection using the TEo, mode in a cubic silver plated cavity.
TCf measurements were made in the interval +80 C to -20 C with the values of 60, 20 and -1 0 C being used to calculate TCf. Er measurements are made using the parallel plate transmission technique of Hakki and Coleman.
In the following Table 1, the names of the compositions prepared by the above describe methods are abbreviated. These abbreviations are summarised as follows: s LZT - La(Zn0 5Tio 5)03 LMT - La(MgO 5Tio 5)03 NZT - Nd(ZnO 5Tio 5)03 NMT - Nd(Mgo 5Tio 5)03 SZT - Sm(ZnO 5Tio 5)03 0 SMT - Sm(MgO 5Tio 5)03 CT- CaTiO3 ST- SrTiO3 ., *.e . e.. . e - e a.. ë -
Table 1
Co m position: Sinter T & t Donsity.r r, / G Q. / $z, M K: LZT 1500 C /8 hr 646 31.8 3200 1240 4000 -81.6 LZT - 0 55 CT 1600 C /4 hr 510 48.0 2 438 7100 17400 18 0.4825 LZT - 0.5175 CT 1600 C /4 hr 5.17 51 0 2 495 6800 17000 6 0 5 LZT - 0 5 CT 1450 C /4 hr 5.18 49.4 2 526 8300 21000 0.6 052 LZT - 0.48 CT 1600 C /4 hr 522 48.6 2.559 6500 16600 -6 0 55 LZT - 0.45 CT 1400 C /24 521 41.7 2.622 8300 21700 -14 hr _ LM T 1600 C /4 hr 5.96 282 3.397 8600 29300 -64 0 35 LM T - 0.65 CT 1550 C /2 hr 467 58.4 2 409 5300 12800 82 0.435 LM T - 0.565 1500 C /4 hr 4.84 48 6 2.549 8000 20100 6 5.
0.45 LMT - 0.55 CT 1500 C /4 hr 4.71 47.7 2.588 9200 23900 1.2..
1 5 0.4525 LMT - 1500 C /4 hr 4.77 40.5 2.580 8500 22000 0.8... . 0.5475 CT..
0 4725 LMT - 1600 C /4 hr 4.92 41 3 2.589 5700 14800 -6 . 0.5275 CT. . . 0.5 LMT - 0.5 CT 1500 C /4 hr 4.75 44.5 2.695 9300 24900 -13.5 0.55 LM T - 0.45 CT 1550 C /4 hr 5.05 41.8 2.731 8100 22000 -26.4 0.65 LMT - 0.35 CT 1500 C /4 hr 4.55 37.6 3.164 3400 10600 O2 NZT 1500 C /8 hr 6.80 27.5 3.440 7850 27000 -53 0.35 NZT - 0.65 CT 1400 C /24 4 95 51.9 2 408 11500 28000 60 0 4 NZT - 0.6 CT hr 5.11 48.7 2.500 9400 23400 34 0.43 NZT - 0.57 CT 1400 C /16 5.21 46.2 2.588 8100 21000 -4 to 22 0.435 NZT - 0.565 1400 C /16 CT hr 5.19 46.3 2.600 8100 21000 4 to 20 0.44 NZT - 0.56 CT 1400 C /16 5.23 46 2 2.603 8500 22100 -6 to 20 0.45 NZT - 0.55 CT hr 5.26 46.8 2 577 12800 33000 -3 to 18 0 5 NZT - 0 5 CT 11550 C / 4 hr 1 5 39 141 4 12 772 134 193 1 -10 to NMT 1600 C /8 hr 6.28 28.5 3 603 15100 54400 -47 NMT - 0.65 CT 1600 C /4 hr 4 80 51 4 2.634 6400 16900 36 NMT- 0.5 CT 1500 C /8 hr 4 99 36 2. 910 9400 27400 -27 SZT 1500 C /8 hr 6 86 26 4 3.508 6800 24000 -27 0.35 SZT- 0.65 CT hr 507 54.7 2.404 12500 30100 66 0.4 SZT - 0.6 CT 1400 C / 8 hr 46.6 2 556 1 1 100 26500 21 0.45 SZT- 0.55 CT 1400 C /8 hr 5.34 45.7 2.632 9700 25500 6 0 5 SZT - 0.5 CT 1400 C / 8 hr 5.51 42.8 2.75 6000 16500 -11 SMT 1600 C /4 hr 6.48 23 7 3.643 5600 21500 -17.
0 35 SMT - 0 65 CT 1500 C / 2 hr 4 87 52.2 2.388 9800 23300 34.
0.5 SMT - 0.5 CT 1550 C / 4 he 5.25 37.4 2.740 9500 26000 0 2. . . ST 1400 C/4 hr 270 2 1500 3000 1200.
CT 170 1.49 8700 12900 800.; Or measured using the parallel plate transmission technique of Hakki & Coleman.
Example 2
All initial starting powders are of purity > 99%. The raw materials are weighed in the appropriate quantities to form the compositions required. Deionised water or isopropan-2-ol are added to the weighed batches which are subsequently ball milled with magnesia stabilised s zirconia milling media for 16 hours. Alternatively, the materials may be attrition milled for 2 hours with yttria stabilized zirconia media. Subsequently, the raw material batches are dried at 80 C and sieved through a 25Olm nylon mesh. The dried powder is calcined (pre form the required phase) at temperatures in the interval 1100 C to 1400 C for 1 to 16 hours. The as- calcined powders are re-milled with 2 wt% PEG binder (MW l O000) for 8 hours, dried and o sieved. Standard test samples of 10 gramme weight are uniaxially pressed in a 20 mm hardened stainless steel die using a pressure of 30 MPa. Sintering of the pellets is performed.
between 1350 and 1700 C for 1 to 48 hours under either an air or oxygen atmosphere. All..
samples are of density > 95% theoretical density using the Archimedes immersion technique.
The electrical properties are tested on the sintered components. Microwave dielectric ..
properties are measured in reflection using the TEA mode in a cubic silver plated cavity. TCf..
measurements are made in the interval +80 C to -20 C with the values of 60, 20 and -l 0 C....
being used to calculate TCf. Er measurements are made using the transmission technique of Hakki and Coleman. /
Composition Densit cr Qf TCf IgYm-3 /GHz /MK-1 ingle dope 0 5 Nd((ZnO4sMgOOs)TiOs)O3 - 0 5 CaT'O3 5.28 44.3 12200 33500 0.9 0.5 Nd((Zn045Mg00s)T'os)o3 - 0.5 CaTiO3 + 0.1 wt% CeO2 5.30 44. 8 13100 35600 1.1 s 0.5 Nd((Zn04sMg0os)T'os)o3 - 0.5 CaTiO3 + 0.5 wt% CeO2 5.28 44.4 13100 35800 1.5 0.5 (Ndo ggCeOO, )((ZnO4sMgO os)Tio5)O3 - 0.5 CaTiO3 5.29 45. 0 13100 35700 0.9 0 5 (NdO99ceoos)((zno4sM9oos)Tios)o3 - 0.5 CaTiO3 5.36 44.6 12800 34900 1. 5.
Nd((Zn0 4sM9oos)Tio49 Nbo00,)O3 - 0.5 CaTiO3 5.15 40.4 12000 32000 Nd((ZnO4sMgOOs)TiO49 Nbooos)O3 - 0.5 CaTiO3 5.32 44.7 12800 34900. ..
0 05 Nd((ZnO4sM90 os)Tio 49 Nboo,)o3 - 0.5 CaTiO3 5.35 44.8 13500 36000 1. 3.. :. e
0.5 Nd((Zno 4sMgo os)Tio 49 Nbo o2)O3 - 0.5 CaTiO3 5.29 43.8 11200 30700. :
Nd((ZnO4sMgOOs)TiO49 Nboos)O3 - 0.5 CaTiO3 5.29 43.3 5900 16300 0.5 Nd((ZnO4sMgOos)Tio49Nbo,)o3 - 0.5 CaTiO3 5.35 43.8 6900 19000 0.5 Nd((Zn04sMg0 os)Tio 49 TaO 0,)O3 - 0.5 CaTiO3 5.29 43.8 13000 35600 1. 1 s 0.5 Nd((ZnO 45Mgo 05)Tio 49 TaO 02)O3 - 0.5 CaTiO3 5.19 42. 4 12400 34400 0.3 Nd((ZnO44AlOO,M90o5)Tio5)o3 - 0.5 CaTiO3 5 35 44. 7 13100 35700 = Jouble dope 0 5 Nd((Zn045Mg005)Tio49 Nbo 0,)O3 - 0.5 CaTiO3 + 5.35 44.6 13000 35500 0.5v4% CeO2
Example 3
All initial starting powders arc of purity > 99%. The La2O3 material is stirred into an excess of water and allowed to dry. After drying, the hydrated lanthanum oxide is evaluated for the moisture content and its weight re-calculated for the dry weight mix. The raw materials are weighed in the appropriate quantities to form the compositions required. Deionised water or isopropan-2-ol are added to the weighed batches which are subsequently ball milled with magnesia stabilised zirconia milling media for 16 hours. Alternatively, the materials may be attrition milled for 2 hours with yttria stabilised zirconia media. Subsequently, the raw material batches are dried at 80 C and sieved through a 250,um nylon mesh. The dried powder is lo calcified (pre form the required phase) at temperatures in the interval 1100 C to 1400 C for I to 16 hours. The as-calcined powders are re-milled with 2 wt% PEG binder (MW 10000) for 8 hours, dried and sieved. Standard test samples of 10 gramme weight are uniaxially pressed in. .
a 20 mm hardened stainless steel die using a pressure of 30 MPa. Sintering of the pellets is performed between 1350 and 1700 C for 1 to 48 hours under either an air or oxygen atmosphere. All samples are of density > 95% theoretical density using the Archimedes....
immersion technique.
::::.
The electrical properties are tested on the sintered components. Microwave dielectric. .:.
properties are measured in reflection using the TEA mode in a cubic silver plated cavity. TCf measurements are made in the interval +80 C to - 20 C with the values of 60, 20 and -10 C being used to calculate TCf. [:r measurements are made using the transmission technique of Hakki and Coleman.
Composition Density Br Q Qf TCf NLC /9 cm3 /GHz /MK' 0.5 La(ZnOsTi05)O3 0.5 CaTiO3 5.21 49.7 12300 31600 1 -0.033 0 5 La(Zn047sAI005Ti047s)o3 0.5 CaTiO3 5.22 49.0 12000 31000 -3.2 -0. 029 2s 1 0.5La(zno4sAio'Tio4s)o3-o.5caTio3 5.21 48.3 11300 29600 1 -7.4 -0.02 0.5 La(Zn04AI02Ti04)O3 - 0.5 CaTiO3 5.19 46.5 11300 30200 -14.3 0.036

Claims (19)

  1. I.A dielectric ceramic material consisting essentially of a composition of Formula 1 xATiO3 (I -x) Re(Z0 sTio s) 3 (1) wherein A may be selected from the group consisting of: Ca, Sr, Mg, Ba and mixtures thereof; Re may be selected from a group consisting of La, Nd or Sm and mixtures thereof; Z may be selected from mixtures of Zn, Mg, Co, Cu. Ni and mixtures thereof; and wherein x is a positive number less than 1.
  2. 2.A material as claimed in claim 1 further comprising a small amount of a dopant selected I. from the group consisting of: MnO2, CeO2 Al2O3, Fe2O3 Nb2O5, Ta2O5, Dy2O3, WO3, Ga2O3, 0 Y2O3, SnO2 and mixtures thereof.
  3. 3.A material as claimed in claim 2 wherein the amount of dopant is 0.005 to 5%.
  4. 4.A material as claimed in any preceding claim further comprising a dopant selected from. ..
    compounds of Eu, Gd, Dy and Pr and mixtures thereof.
  5. 5.A dielectric material consisting essentially of a composition of Formula 4: CaTiO3-Nd(Zn05Ti05)O3 ( )
  6. 6.A dielectric material consisting essentially of a composition of Formula 5: CaTiO3 - Nd(Mgo sTio 5)O3 (5)
  7. 7.A dielectric material consisting essentially of a composition of Formula 6: CaTiO3 - Sm(Zn0 sTio 5)O3 (6)
  8. 8.A dielectric material consisting essentially of a composition of Formula 7: CaTiO3 - Sm(MgO sTio 5)O3 ( )
  9. 9. A dielectric material consisting essentially of a composition of Formulae 8: a Nd((ZncMg'c)bTi b) 3 + (1-a) (Caxsri-x)Tio3 (8) wherein 0.4<a < 0.6 0.4 < b 0.6 0 < c < 0.2 isfrom 1 toO.9 0
  10. 10. A dielectric material consisting essentially of a composition of Formulae 9: 0 5 Nd((Zno 4sMg0 05)Ti0 5)O3 + 0 5 CaTiO3 (9) . .
  11. 1 1. A dielectric material consisting essentially of a composition of Formulae 10 to 26: 0 5 Nd((Zno45Mgoo5)Tio5)O3 + 0.5 CaTiO3 + 0.1 wt% CeO2 (10) ...
    0 5 Nd((ZnO45Mgo05)Tio49Nboo)O3 + 0.5 CaTiO3 + 0.5 wt% CeO2 (I 1) .. :.
    0 5 (Nd099ceoo)((zno45Mgoo5)Tio5)o3 + 0.5 CaTiO3 (12) 0 5 Nd((Zno4sMgoos)Tio49Nboo)o3 + 0.5 CaTiO3 (13) .: 0.5 Nd((ZnO45Mg0o5)Tio49Taoo)o3 + 0.5 CaTiO3 (14) 0.5 Nd((ZnO 44AIo oMgo 05)Tio 5)O3 + 0.5 CaTiO3 (15) 0.55 CaTiO3 + 0.45 La(Zn0395Ti0395AI02)O3 doped with 0.005 to 5 wt% CeO2 (16) 0.55 CaTiO3 + 0.45 La(Zn0395Ti0395AI02)O3doped with 0.005 to 5 wt% Ta2O5 (17) 0.55 CaTiO3 + 0.45 La(ZnO 395Tio 395Alo 2)O3 doped with 0.005 to 5 wt% Nb2O5 (18) 0.55 CaTiO3 + 0.45 La(ZnO395Tio395Alo2,)O3 doped with 0.005 to 5 wt% CoO (19) 0 55 (Ca-xsrx)Tio3 + 045 La(Zn0 395Tio 395Alo 2)O3 doped with 0.005 to 5 wt% CeO2 where x is between 0.001 and 0.10. (20) 0.55 (Ca xSrx)TiO3 + 0.45 La(Zn0395Ti0395AI02)O3doped with 0.005 to 5 wt% Ta2O5 where x is between 0.001 and 0.10. (21) 0.55 (Cal xSrx)TiO3 + 0.45 La(ZnO 395Tio395AI02)o3 doped with 0.005 to 5 wt% Nb2O5.
    where x is between 0.001 and 0.10. (22) 0 55 (Ca-xSrx)Tio3 + 0 45 La(Zn0395Ti0395AIi2)O3doped with 0.005 to 5 wt% CoO where x is between 0.001 and 0.10. (23) A CaTiO3 + (1-A) Nd((Zno4sMgoos)xTio 5Aly))03 doped with 0.005 to 5 wt% CeO2 where A is between 0.35 and 0.65.
    x is between 0.]5 and 0.49. y is between 0.01 and 0.35 (24) A CaTiO3 + (1A) Nd((Zno45Mgoo5)xTio5Aly))O3 doped with 0.005 to 5 wt% Ta2O5 0 where A is between 0.35 and 0.65.
    x is between 0.15 and 0.49. y is between 0.01 and 0.35 (25) A CaTiO3 + (IA) Nd((Zno45Mgoo5)xTio5AIy))O3 doped with 0.005 to 5 wt% Nb2O5 where A is between 0.35 and 0.65.
    x is between 0.15 and 0.49. y is between 0.01 and 0.35 (26) .. .
  12. 12. A material of claim
  13. 13 co-doped with a manganese compound equivalent to up to 1 % . MnO2. 13. A dielectric material consisting essentially of a composition of Formula 27: : a La(ZncMgdTibAle(Nb or Ta or Ce)f)03 + (1-a) (CagSr' g) TiO3 .
    (27) . . wherein. :.
    0.4 < a < 0.6 0 < b < 0.5 0< c < 0.5 0 < d 0.5 0 e < 0.8 0< f 0.2 0 < g < 1.0 whereb+c+d+e+f= 1
  14. 14. A dielectric material consisting essentially of a composition of Formulae 28 to 34: 0.5 La(ZnO5Ti05)O3 + 0.5 CaTiO3 (28) 0.5 La((Zn0475Al005)Ti0475) 3 + 0.5 CaTiO3 to 0.5 La(ZnO Halo ratio ')O3 + 0.5 CaTiO3 (29) 0.5 La((Zn0 47sAlo 05)Tio 475)O3 + 0.5 CaTiO3 to 0.5 La(Zn0 IAlo 8Tio,)O3 + 0.5 CaTiO3 plus 0.1 to 0.5 wt% CeO2 0.5 (La099Ce00)(zn45Alo Tio45)o3 + 0 5 CaTiO3 (31) 0.5 La(Zn045AI0 05Tio45)O3 + 0 5 CaTiO3 doped in amounts up to 0.1 moles Nb205 (32) 0.5 La(Zn045AI005Tio45)o3 - 0.5 CaTiO3 doped in amounts up to 0.1 moles Ta2O5 (33) 0.5 La(Zn045Al005Ti045)O3 + 0.5 CaTiO3 doped in amounts up to 1 mole SrO for CaO (34)
  15. 15. A dielectric material consisting essentially of a composition formula (35): .
    a Nd(ZncMgdTib Ale(Nb or Ta or Ce)f)O3 + ( 1 -a) (CagSr g)TiO3.... - ,.
    0.4 < a < 0.6 : O < b < 0.5.. .
    O < c < 0.5 O<d<0.5 O<e<0.8 ' 0<f<0.2. :.
    O < g < 1.0
  16. 16. A dielectric material of claim 15 co-doped with a manganese compound equivalent to up to 1% MnO2.
  17. 17. A dielectric material consisting eventually of a composition of Formulae 36 to 39: 0 32 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3. (36) 032 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3 plus 0.005 to S wt% CeO2. (37) 032 Nd(Zn045Mg005Ti05)O3 + 01 NdAIO3 + 0.58 CaTiO3 plus 0.005 to 5 wt% Nb2O5. (38) 0 32 Nd(Zn045Mg005Ti05)O3 + 0.1 NdAIO3 + 0.58 CaTiO3 plus 0.005 to 5 wt% Ta2O5. (39)
  18. 18. A dielectric material of claim 17 co-doped with a manganese compound equivalent to up to 1% MnO2.
  19. 19. A dielectric material substantially as hereinbefore described with reference to the
    examples. ä ei. : -a. ë -. ë , e
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US7326667B2 (en) 2005-08-10 2008-02-05 Remec International Holdings Srl Microwave dielectric ceramic
CN103601481A (en) * 2013-09-16 2014-02-26 南通万宝实业有限公司 Preparation method of novel rare earth co-doped FB9 permanent magnet used for variable frequency motor

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CN113336539A (en) * 2021-07-01 2021-09-03 无锡市高宇晟新材料科技有限公司 Microwave dielectric ceramic material, preparation method and application

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JPH0817246A (en) * 1994-06-30 1996-01-19 Korea Advanced Inst Of Sci Technol Dielectric composition for high frequency
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Cited By (3)

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Publication number Priority date Publication date Assignee Title
US7326667B2 (en) 2005-08-10 2008-02-05 Remec International Holdings Srl Microwave dielectric ceramic
CN103601481A (en) * 2013-09-16 2014-02-26 南通万宝实业有限公司 Preparation method of novel rare earth co-doped FB9 permanent magnet used for variable frequency motor
CN103601481B (en) * 2013-09-16 2015-07-15 南通万宝实业有限公司 Preparation method of novel rare earth co-doped FB9 permanent magnet used for variable frequency motor

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