DE1796226B2 - Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramics - Google Patents
Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramicsInfo
- Publication number
- DE1796226B2 DE1796226B2 DE1796226A DE1796226A DE1796226B2 DE 1796226 B2 DE1796226 B2 DE 1796226B2 DE 1796226 A DE1796226 A DE 1796226A DE 1796226 A DE1796226 A DE 1796226A DE 1796226 B2 DE1796226 B2 DE 1796226B2
- Authority
- DE
- Germany
- Prior art keywords
- temperature
- temperature dependence
- ceramic
- titanate
- stabilizing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000919 ceramic Substances 0.000 title claims description 13
- 238000000034 method Methods 0.000 title claims description 10
- 230000000087 stabilizing effect Effects 0.000 title 1
- 239000000463 material Substances 0.000 claims description 9
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 claims description 6
- 229910052451 lead zirconate titanate Inorganic materials 0.000 claims description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims 1
- 229910052779 Neodymium Inorganic materials 0.000 claims 1
- 238000003754 machining Methods 0.000 claims 1
- 229910052749 magnesium Inorganic materials 0.000 claims 1
- 239000011777 magnesium Substances 0.000 claims 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims 1
- 229910052721 tungsten Inorganic materials 0.000 claims 1
- 239000010937 tungsten Substances 0.000 claims 1
- 239000010936 titanium Substances 0.000 description 8
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 229910052726 zirconium Inorganic materials 0.000 description 3
- 229910017493 Nd 2 O 3 Inorganic materials 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 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
- C04B35/46—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 titanium oxides or titanates
-
- 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
- C04B35/48—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 zirconium or hafnium oxides, zirconates, zircon or hafnates
-
- 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
- C04B35/48—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 zirconium or hafnium oxides, zirconates, zircon or hafnates
- C04B35/49—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 zirconium or hafnium oxides, zirconates, zircon or hafnates containing also titanium oxides or titanates
- C04B35/491—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 zirconium or hafnium oxides, zirconates, zircon or hafnates containing also titanium oxides or titanates based on lead zirconates and lead titanates, e.g. PZT
-
- 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
- C04B35/50—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds
-
- 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
- C04B35/51—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on compounds of actinides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G7/00—Capacitors in which the capacitance is varied by non-mechanical means; Processes of their manufacture
- H01G7/02—Electrets, i.e. having a permanently-polarised dielectric
- H01G7/025—Electrets, i.e. having a permanently-polarised dielectric having an inorganic dielectric
- H01G7/026—Electrets, i.e. having a permanently-polarised dielectric having an inorganic dielectric with ceramic dielectric
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/04—Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
- H10N30/853—Ceramic compositions
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Structural Engineering (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Compositions Of Oxide Ceramics (AREA)
Description
Die Erfindung betrifft ein Verfahren zur Beseitigung der Zeitabhängigkeit des Temperaturverhaltens der materialabhängigen Frequenzkonstanten piezoelektrischer Keramik.The invention relates to a method for eliminating the time dependency of the temperature behavior the material-dependent frequency constants of piezoelectric ceramics.
Es ist bekannt, piezoelektrische Keramik als elektromechanische Umsetzer in mechanischen Filtern für die Elektronik zu verwenden. Bei dieser Verwendung der Keramik spielt die Temperaturabhängigkeit der Frequenzkonstanten der mechanischen Schwingung der Keramik eine ganz wesentliche Rolle. Es sind viele Versuche angestellt worden, diese Temperaturabhängigkeit möglichst klein zu machen. Ein Weg, der hierzu beschritten wurde, ist derjenige, ein homogenes Material aus mehreren Komponenten zu verwenden. Ein typischer Vertreter hierfür ist das Bleizirkonat-Titanat mit in bestimmten Grenzen festgelegtem Verhältnis Titan zu Zirkon. Gegebenenfalls sind einem solchen Material noch weitere Stoffe als Dotierung oder Substitution hinzugefügt. So wurde gefunden, daß sich die Temperaturabhängigkeit der Frequenzkonstanten bei Bleizirkonat-Titanat, insbesondere bei Zusammensetzungen Zirkon zu Titan im Bereich der Phasengrenze zwischen rhomboedrischer und tetragonaler Struktur besonders stark beeinflussen läßt. Vorteilhafterweise sind an dieser Phasengrenze auch besonders hohe Kopplungsfaktoren festzustellen. It is known to use piezoelectric ceramics as electromechanical To use converters in mechanical filters for electronics. In this use the ceramic plays the temperature dependence of the frequency constants of the mechanical vibration ceramics play a very important role. Many attempts have been made to find this temperature dependence to make it as small as possible. One path that has been taken to achieve this is one to use homogeneous material made up of several components. A typical representative of this is that Lead zirconate titanate with a fixed ratio of titanium to zirconium within certain limits. Possibly other substances are added to such a material as doping or substitution. So became found that the temperature dependence of the frequency constants in lead zirconate titanate, in particular in the case of compositions zirconium to titanium in the area of the phase boundary between rhombohedral and tetragonal structure can be influenced particularly strongly. Advantageously, are at this phase boundary also determine particularly high coupling factors.
Es wurde aber festgestellt, daß die Temperaturabhängigkeit eines wie oben beschriebenen Materials nicht zeitunabhängig ist, sondern daß sie sich nach Vornahme eines Bearbeitungsvorganges, z. B. nach dem Zuschneiden, nach dem Aufbringen der Elektroden und'oder nach der Polarisation des Materials noch für lange Zeit ändert.However, it was found that the temperature dependence of a material as described above is not time-independent, but that it is after performing a processing operation, z. B. after after cutting, after applying the electrodes and 'or after polarizing the material will change for a long time.
Aufgabe der Erfindung ist es, Maßnahmen anzugeben, mit denen die langzeitliche Änderung der Temperaturabhängigkeit der Frequenzkonstante beseitigt werden kann bzw. durch die der darin verborgene Alterungseffekt wesentlich beschleunigt werden kann.The object of the invention is to provide measures with which the long-term change in Temperature dependence of the frequency constant can be eliminated or by which the hidden therein The aging effect can be accelerated significantly.
ίο Diese Aufgabe wird durch ein Verfahren gelöst, das erfindungsgemäß dadurch gekennzeichnet ist, daß ein polarisierter Keramikkörper nach der letzten Erwärmung auf Temperaturen höher als etwa 80° C mehrmalig aufeinanderfolgend einem Temperaturzyklus unterworfen wird, bei dem das Material mit einer Geschwindigkeit von höchstens etwa 30° C/h bis auf eine vom Material abhängige Maximaltemperatur unterhalb der Curietemperatur erwärmt und wieder auf die vorgesehene Betriebstemperatur, vorzugsweise die Zimmertemperatur, abgekühlt wird. Diese Maximaltemperatur beträgt, insbesondere für Bleizirkonat-Titanat mit einem Verhältnis Zirkon zu Titan im Bereich der Phasengrenze, etwa 80° C. In vielen Fällen genügt es bereits, den Temperaturzyklus 3- bis 4mal ablaufen zu lassen. Bezüglich der angegebenen Geschwindigkeit ist zu sagen, daß bei langsamerer Erwärmung oder Abkühlung etwa mit 10 oder 20° C/h im allgemeinen noch mehr Erfolg erzielt wird. Dabei ist aber zu bedenken, daß ein so langsam ablaufender Prozeß fertigungstechnisch häufig unerwünscht ist. Aus diesen Angaben kann sich der Fachmann im übrigen die für den jeweiligen Anwendungsfall günstigste Geschwindigkeit auswählen. ίο This task is solved by a method which is characterized according to the invention in that a polarized ceramic body after the last Heating to temperatures higher than about 80 ° C several times in succession in a temperature cycle is subjected, in which the material at a rate of at most about 30 ° C / h heated to a maximum temperature below the Curie temperature, depending on the material, and is cooled again to the intended operating temperature, preferably room temperature. This maximum temperature is, in particular for lead zirconate-titanate with a ratio of zirconium to Titanium in the area of the phase boundary, around 80 ° C. In many cases, it is enough to just start the temperature cycle To run 3 to 4 times. With regard to the specified speed, it should be said that at Slower heating or cooling at around 10 or 20 ° C / h is generally more successful is achieved. It should be noted, however, that such a slow process is technically manufacturing is often undesirable. From this information, the person skilled in the rest of the for the respective Select the best speed for use case.
Zu der Erfindung führten die folgenden Überlegungen: Den Untersuchungen nach zu schließen, dürfte die zeitliche Änderung der Temperaturabhängigkeit der Frequenzkonstanten der piezoelektrischen Keramik darauf beruhen, daß sich nach einem mit einer Erwärmung der Keramik verbundenen Bearbeitungsprozeß der thermodynamische Gleichgewichtszustand nur sehr langsam einstellt. Es liegen also praktisch eingefrorene Zustände vor, die nun durch das erfindungsgemäße Verfahren beschleunigt in ein Gleichgewicht übergeführt werden. Wie sich gezeigt hat, darf der erfindungsgemäße Temperaturzyklus bei Bleizirkonat-Titanat nur bis zu einer Temperatur von etwa 80° C ausgedehnt werden. Temperaturen wesentlich darüber, etwa über 100° C, bringen erfahrungsgemäß eher Nachteile als Vorteile. Wesentlich unter 80° C zu bleiben hat sich wenigstens im allgemeinen Fall wenig bewährt. Bei zu niedrigen Endtemperaturen mußten nämlich, um das gleiche Ergebnis zu erreichen, wesentlich mehr Temperaturzyklen durchgeführt werden, als sie bei z. B. 80° C Endtemperatur erforderlich waren. Als besonders wirkungsvoll erwies sich das erfindungsgemäße Verfahren bei Materialien wieThe following considerations led to the invention: According to the investigations, to conclude is likely to be the change over time of the temperature dependence of the frequency constants of the piezoelectric Ceramic are based on the fact that after a processing process associated with heating the ceramic the thermodynamic state of equilibrium adjusts only very slowly. So there are practically frozen states, which are now accelerated by the method according to the invention into a Balance to be transferred. As has been shown, the temperature cycle according to the invention may in the case of lead zirconate titanate, can only be expanded up to a temperature of about 80 ° C. Temperatures experience shows that significantly above this, for example above 100 ° C, have disadvantages rather than advantages. Essential Staying below 80 ° C has proven to be of little use, at least in the general case. If the final temperature is too low namely, had to achieve the same result, significantly more temperature cycles be carried out as they are at z. B. 80 ° C final temperature were required. As special The method according to the invention proved to be effective with materials such as
Pb Zr 0,54, Ti 0,46 O3 + 1 «/0 Nd2O3,Pb Zr 0.54, Ti 0.46 O 3 + 1 «/ 0 Nd 2 O 3 ,
Pb Zr 0,51, Ti 0,49 O3 + l,2°/oMnÖ„,Pb Zr 0.51, Ti 0.49 O 3 + 1.2 ° / oMnÖ ",
Pb Zr 0,49, Ti 0,51 O3 + 0,5 Vo Fe2OJ,Pb Zr 0.49, Ti 0.51 O 3 + 0.5 Vo Fe 2 OJ,
Pb Zr 0,57, Ti 0,43 O3 + 0,5 % Fe2O3,Pb Zr 0.57, Ti 0.43 O 3 + 0.5% Fe 2 O 3 ,
Pb Zr 0,45, Ti 0,40 (Mg 0,075, Wo 0,075) O3.Pb Zr 0.45, Ti 0.40 (Mg 0.075, Wo 0.075) O 3 .
Die Prozentangaben sind Gewichtsprozente.The percentages are percentages by weight.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1796226A DE1796226C3 (en) | 1968-09-25 | 1968-09-25 | Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1796226A DE1796226C3 (en) | 1968-09-25 | 1968-09-25 | Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramics |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| DE1796226A1 DE1796226A1 (en) | 1972-04-27 |
| DE1796226B2 true DE1796226B2 (en) | 1975-03-06 |
| DE1796226C3 DE1796226C3 (en) | 1975-10-23 |
Family
ID=5708403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE1796226A Expired - Lifetime DE1796226C3 (en) | 1968-09-25 | 1968-09-25 | Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramics |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE1796226C3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3125624B2 (en) * | 1995-04-21 | 2001-01-22 | 株式会社村田製作所 | Piezoelectric ceramic |
-
1968
- 1968-09-25 DE DE1796226A patent/DE1796226C3/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE1796226A1 (en) | 1972-04-27 |
| DE1796226C3 (en) | 1975-10-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE1105920B (en) | Use of a solid solution of lead titanate and lead zirconate as a piezoelectric, ceramic element | |
| DE1646864C3 (en) | Stabilized refractory ceramics based on zirconia and processes for their production | |
| DE10039397A1 (en) | Production of a piezoelectric ceramic used e.g. for ceramic filters and resonators comprises heating a ceramic mixture to a temperature lying above the melting point of the mixture, and cooling and solidifying the molten mixture | |
| DE1796226B2 (en) | Method for stabilizing the temperature dependence of the frequency constants of piezoelectric ceramics | |
| DE102009029511A1 (en) | Ceramic material for a piezoelectric actuator and / or sensor device and method for producing a ceramic material for a piezoelectric actuator and / or sensor device | |
| DE1796233C2 (en) | Piezoelectric ceramics | |
| DE2507395A1 (en) | METHOD OF MANUFACTURING FERROELECTRIC CERAMIC MATERIALS | |
| DE1940974B2 (en) | Piezoelectric ceramics | |
| DE1950317C3 (en) | Piezoelectric ceramics | |
| DE1063655B (en) | Process for the production of an element for converting mechanical energy into electrical energy or vice versa | |
| DE2557678C3 (en) | Process for making a pyroelectric material | |
| DE1796244A1 (en) | Piezoelectric ceramic masses | |
| DE2040573C3 (en) | Piezoelectric ceramics | |
| DE102021106699A1 (en) | Process for precipitation hardening of a piezoceramic and piezoceramic | |
| DE1131758B (en) | Process to improve piezoelectric ceramics and to reduce the effects of aging | |
| DE739420C (en) | Ceramic insulating body | |
| DE1202701B (en) | Process for the production of a largely hydration-resistant sinter from dolomite, magnesite or lime | |
| DE1671166B1 (en) | PIEZOELECTRIC CERAMIC MATERIAL | |
| DE1646525C3 (en) | Piezoelectric ceramics | |
| DE975985C (en) | Process for producing an electrical resistor with a negative temperature coefficient | |
| DE824699C (en) | Process for polarizing a ceramic electromechanically sensitive transducer material | |
| DE1805575A1 (en) | Piezoelectric ceramic masses | |
| DE1471166A1 (en) | Modified lead-titanate-zirconate-ceramic mixture and process for its production | |
| CH378762A (en) | Piezoelectric converter | |
| DE2255143C3 (en) | Ferroelectric ceramics and ceramic base materials therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C3 | Grant after two publication steps (3rd publication) |