JP2007055864A - Piezoelectric ceramic composition - Google Patents
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本発明は、ニオブ酸系の圧電磁器に関するものであり、更に詳しくは、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の相転移温度を室温以下まで降下させることを可能とする新規ニオブ酸系圧電磁器組成物に関するものである。本発明は、圧電磁器及び圧電素子、特に、圧電フィルタ及び圧電アクチュエータに好適に使用することが可能な新規ニオブ酸アルカリ系圧電磁器組成物及びその製品を提供するものである。 The present invention relates to a niobic acid-based piezoelectric ceramic, and more specifically, a novel niobic acid-based system that can lower the phase transition temperature of a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 to room temperature or lower. The present invention relates to a piezoelectric ceramic composition. The present invention provides a novel alkali niobate-based piezoelectric ceramic composition that can be suitably used for piezoelectric ceramics and piezoelectric elements, in particular, piezoelectric filters and piezoelectric actuators, and products thereof.
本発明の圧電磁器は、従来材の室温〜１００℃付近に相転移点が存在し、圧電素子の使用温度範囲において圧電特性の著しい変化を生じることで実用化が困難であったニオブ酸系圧電磁器について、その相転移温度を室温以下に降下させて、該ニオブ酸系圧電磁器の実用化を可能にするための新技術・新製品を提供するものである。 The piezoelectric ceramic of the present invention has a phase transition point between room temperature and about 100 ° C. of a conventional material, and a niobic acid type piezoelectric material that has been difficult to put into practical use due to a significant change in piezoelectric characteristics in the operating temperature range of the piezoelectric element. With respect to porcelain, a new technology and a new product are provided for lowering the phase transition temperature to room temperature or lower to enable practical use of the niobic acid-based piezoelectric ceramic.
近年、自然環境に対して有害な酸化鉛を含有せず、比較的良好な圧電性を示すセラミック材料として、ニオブ酸アルカリ系の圧電磁器が注目されている。ニオブ酸アルカリ系の圧電磁器としては、例えば、ニオブ酸リチウムナトリウムを基本組成とする固溶体に副成分として、酸化アルミニウム、酸化鉄を添加した高密度で機械的強度が大きい圧電磁器が提案されている（特許文献１参照）。また、ニオブ酸カリウムとニオブ酸ナトリウムを主成分とした圧電磁器として、これに銅を添加して焼結性を改善した組成物、リチウム及びタンタルを添加することにより温度特性を高くした組成物が提案されている（特許文献２参照）。 In recent years, alkaline niobate-based piezoelectric ceramics have attracted attention as ceramic materials that do not contain lead oxide harmful to the natural environment and exhibit relatively good piezoelectricity. As an alkali niobate-based piezoelectric ceramic, for example, a piezoelectric ceramic having a high density and high mechanical strength is proposed in which aluminum oxide and iron oxide are added as subcomponents to a solid solution having lithium sodium niobate as a basic composition. (See Patent Document 1). In addition, as a piezoelectric ceramic mainly composed of potassium niobate and sodium niobate, a composition in which copper is added to improve the sintering property, and a composition having improved temperature characteristics by adding lithium and tantalum are provided. It has been proposed (see Patent Document 2).
ニオブ酸カリウム（ＫＮｂＯ３）とニオブ酸ナトリウム（ＮａＮｂＯ３）を主成分とした圧電磁器、例えば、先行文献に開示されているＬｉ（Ｋ，Ｎａ）（Ｎｂ，Ｔａ，Ｓｂ）Ｏ３系セラミックスは、キュリー温度が高く、比較的高い電気機械結合係数を有することから圧電素子としての利用が考えられている（特許文献３参照）。更に、Ｌｉ（Ｋ，Ｎａ）（Ｎｂ，Ｔａ）Ｏ３系セラミックスに、Ｍｇ、Ｃａ、Ｓｒ等の２価の金属、Ｔｉ、Ｚｒ、Ｓｎ等の４価の金属を有する高周波領域での使用に適した圧電磁器が提案されている（特許文献４）。 Piezoelectric ceramics mainly composed of potassium niobate (KNbO 3 ) and sodium niobate (NaNbO 3 ), for example, Li (K, Na) (Nb, Ta, Sb) O 3 ceramics disclosed in the prior art Since the Curie temperature is high and the electromechanical coupling coefficient is relatively high, use as a piezoelectric element is considered (see Patent Document 3). In addition, Li (K, Na) (Nb, Ta) O 3 based ceramics, divalent metals such as Mg, Ca and Sr, and tetravalent metals such as Ti, Zr and Sn are used in a high frequency region. A suitable piezoelectric ceramic has been proposed (Patent Document 4).
従来のＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器については、比較的高い電気機械結合係数及び高い圧電歪定数を示すものの、組成に応じて、室温〜１００℃付近に斜方晶から正方晶に相転移する温度、いわゆる相転移点が存在する。しかし、この相転移点の存在は、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とした圧電素子の使用温度範囲内において、圧電特性の著しい変化を生じさせることから、従来、このことが、ＫＮｂＯ３−ＮａＮｂＯ３系圧電磁器の製品化への障害となっていた。 The piezoelectric ceramic mainly composed of conventional KNbO 3 -NaNbO 3, although a relatively high electromechanical coupling factor and a high piezoelectric strain constant, depending on the composition, tetragonal from orthorhombic to about room temperature to 100 ° C. There is a so-called phase transition point. However, the presence of this phase transition point causes a significant change in the piezoelectric characteristics within the operating temperature range of the piezoelectric element mainly composed of KNbO 3 —NaNbO 3 , and thus this has conventionally been known as KNbO 3 —NaNbO. It was an obstacle to the commercialization of 3 series piezoelectric ceramics.
このような状況の中で、本発明者は、上記従来技術に鑑みて、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の圧電特性及び相転移温度を改良して実用化可能な圧電磁器を作製することを目標として鋭意研究を重ねた結果、上記２成分系の圧電磁器の組成の一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時置換して４成分系の組成物とすることにより上記圧電磁器の相転移温度を室温以下に降下させることができることを見出し、更に研究を重ねて、本発明を完成するに至った。 Under such circumstances, in view of the prior art, the present inventor has developed a piezoelectric ceramic that can be put into practical use by improving the piezoelectric characteristics and phase transition temperature of a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3. As a result of earnest research for the purpose of production, a part of the composition of the two-component piezoelectric ceramic is simultaneously replaced with LiNbO 3 and CaTiO 3 to form a four-component composition. The inventors have found that the phase transition temperature can be lowered to room temperature or lower, and have further researched to complete the present invention.
本発明は、新規ニオブ酸アルカリ系圧電磁器組成物を提供することを目的とするものである。また、本発明は、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の相転移温度を室温以下に降下させることを実現した新規４成分系圧電磁器組成物を提供することを目的とするものである。また、本発明は、上記圧電磁器組成物を圧電素子として使用する圧電部材を提供することを目的とするものである。 An object of the present invention is to provide a novel alkali niobate piezoelectric ceramic composition. Another object of the present invention is to provide a novel four-component piezoelectric ceramic composition that realizes lowering the phase transition temperature of a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 to room temperature or lower. is there. Another object of the present invention is to provide a piezoelectric member that uses the piezoelectric ceramic composition as a piezoelectric element.
上記課題を解決するための本発明は、以下の技術的手段から構成される。
（１）ＫＮｂＯ３−ＮａＮｂＯ３を主要構成成分とする圧電磁器であって、（１）該圧電磁器の組成の一部がＬｉＮｂＯ３及びＣａＴｉＯ３で置換されていること、（２）該圧電磁器の相転移温度が室温以下に降下されていること、を特徴とする圧電磁器。
（２）上記圧電磁器が、副成分としてＭｎＣＯ３及び／又はＬａ２Ｏ３を含む、前記（１）に記載の圧電磁器。
（３）Ｎａ、Ｋ、Ｌｉ、Ｃａ、Ｎｂ、Ｔｉを主成分とするペロブスカイト化合物を主体とした圧電磁器であって、モル比による組成式を、次の式；
（１−ｘ−ｙ）ＫＮｂＯ３＋ｘＮａＮｂＯ３＋ｙ（ＬｉＮｂＯ３＋ＣａＴｉＯ３）
とした時、ｘ及びｙの値が、０．４０≦ｘ≦０．５０、０．０３≦ｙ≦０．１１を満たす、前記（１）に記載の圧電磁器。
（４）上記圧電磁器が、副成分としてＭｎをＭｎＣＯ３換算で１ｗｔ％以下及び／又はＬａをＬａ２Ｏ３換算で１ｗｔ％以下含む、前記（２）に記載の圧電磁器。
（５）前記（１）から（４）のいずれかに記載の圧電磁器を主要材料として含むことを特徴とする圧電素子。
（６）前記（５）に記載の圧電素子を構成要素として含むことを特徴とする圧電部材。
（７）ＫＮｂＯ３−ＮａＮｂＯ３を主要構成成分とする圧電磁器の組成の一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時置換することにより圧電磁器の相転移温度を室温以下に降下させることを特徴とする圧電磁器の製造方法。
（８）上記圧電磁器に、副成分としてＭｎＣＯ３及び／又はＬａ２Ｏ３を配合する、前記（７）に記載の方法。
The present invention for solving the above-described problems comprises the following technical means.
(1) A piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 , wherein (1) a part of the composition of the piezoelectric ceramic is replaced with LiNbO 3 and CaTiO 3 , (2) the piezoelectric ceramic A piezoelectric ceramic characterized in that the phase transition temperature of is lowered to room temperature or lower.
(2) The piezoelectric ceramic according to (1), wherein the piezoelectric ceramic includes MnCO 3 and / or La 2 O 3 as subcomponents.
(3) A piezoelectric ceramic mainly composed of a perovskite compound mainly composed of Na, K, Li, Ca, Nb, and Ti, wherein the composition formula based on the molar ratio is expressed by the following formula:
(1-xy) KNbO 3 + xNaNbO 3 + y (LiNbO 3 + CaTiO 3 )
The piezoelectric ceramic according to (1), wherein the values of x and y satisfy 0.40 ≦ x ≦ 0.50 and 0.03 ≦ y ≦ 0.11.
(4) The piezoelectric ceramic according to (2), wherein the piezoelectric ceramic contains 1 wt% or less in terms of MnCO 3 and / or 1 wt% or less in terms of La 2 O 3 as an auxiliary component.
(5) A piezoelectric element comprising the piezoelectric ceramic according to any one of (1) to (4) as a main material.
(6) A piezoelectric member comprising the piezoelectric element according to (5) as a constituent element.
(7) A part of the composition of a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 is replaced with LiNbO 3 and CaTiO 3 simultaneously to lower the phase transition temperature of the piezoelectric ceramic below room temperature. A method of manufacturing a piezoelectric ceramic.
(8) The method according to (7), wherein MnCO 3 and / or La 2 O 3 is blended in the piezoelectric ceramic as a subcomponent.
次に、本発明について更に詳細に説明する。
本発明の圧電磁器は、Ｎａ、Ｋ、Ｌｉ、Ｃａ、Ｎｂ、Ｔｉを主成分とするペロブスカイト化合物を主体とした圧電磁器であって、モル比による組成式を、次の式；
（１−ｘ−ｙ）ＫＮｂＯ３＋ｘＮａＮｂＯ３＋ｙ（ＬｉＮｂＯ３＋ＣａＴｉＯ３）
とした時、ｘ及びｙの値が、０．４０≦ｘ≦０．５０、０．０３≦ｙ≦０．１１を満足する組成を有することを特徴とするものである。
Next, the present invention will be described in more detail.
The piezoelectric ceramic of the present invention is a piezoelectric ceramic mainly composed of a perovskite compound mainly composed of Na, K, Li, Ca, Nb, and Ti.
(1-xy) KNbO 3 + xNaNbO 3 + y (LiNbO 3 + CaTiO 3 )
In this case, the x and y values have a composition satisfying 0.40 ≦ x ≦ 0.50 and 0.03 ≦ y ≦ 0.11.
ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器については、組成に応じて、室温〜１００℃付近に相転移点が存在し、この相転移現象の存在が原因となって、実用化への障害となっていた。本発明では、これらの組成の一部をニオブ酸リチウム（ＬｉＮｂＯ３）及びチタン酸カルシウム（ＣａＴｉＯ３）で同時に置換することによって、斜方晶から正方晶への相転移温度を室温以下まで降下させることが可能である。ここで、同時に置換とは、圧電磁器の組成として、ニオブ酸カリウム及びニオブ酸ナトリウムに加えてニオブ酸リチウム及びチタン酸カルシウムの両方が必ず含まれていることを意味する。本発明の圧電磁器を使用することによって、環境に優しい鉛を含まない実用化可能な特性を有するニオブ系圧電素子を製造することが可能になる。 For a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 , there is a phase transition point between room temperature and 100 ° C. depending on the composition, and this phase transition phenomenon causes the obstacle to practical use. It was. In the present invention, a part of these compositions is simultaneously substituted with lithium niobate (LiNbO 3 ) and calcium titanate (CaTiO 3 ), thereby lowering the phase transition temperature from orthorhombic to tetragonal to below room temperature. It is possible. Here, simultaneous substitution means that the composition of the piezoelectric ceramic always includes both lithium niobate and calcium titanate in addition to potassium niobate and sodium niobate. By using the piezoelectric ceramic according to the present invention, it is possible to manufacture a niobium-based piezoelectric element having characteristics that can be put into practical use and does not contain environmentally friendly lead.
本発明の圧電磁器は、Ｎａ、Ｋ、Ｌｉ、Ｃａ、Ｎｂ、Ｔｉを主成分とするペロブスカイト化合物を主体とした圧電磁器の組成について、モル比による組成式を、次の式；
（１−ｘ−ｙ）ＫＮｂＯ３＋ｘＮａＮｂＯ３＋ｙ（ＬｉＮｂＯ３＋ＣａＴｉＯ３）
とした時、ｘ及びｙの値が、０．４０≦ｘ≦０．５０、０．０３≦ｙ≦０．１１を満たす組成とすることが重要である。更に、本発明では、この圧電磁器に、副成分としてＭｎをＭｎＣＯ３換算で１ｗｔ％以下及び／又はＬａをＬａ２Ｏ３換算で１ｗｔ％以下を配合して、これらを含む組成を有する圧電磁器とすることができる。
The piezoelectric ceramic of the present invention is a composition of a piezoelectric ceramic mainly composed of a perovskite compound mainly composed of Na, K, Li, Ca, Nb, and Ti.
(1-xy) KNbO 3 + xNaNbO 3 + y (LiNbO 3 + CaTiO 3 )
In this case, it is important that the composition satisfies the values of x and y satisfying 0.40 ≦ x ≦ 0.50 and 0.03 ≦ y ≦ 0.11. Furthermore, in the present invention, a piezoelectric ceramic having a composition containing Mn as an auxiliary component and 1% by weight or less in terms of MnCO 3 and / or 1% by weight or less in terms of La 2 O 3 as a subsidiary component. It can be.
前記構成において、ＮａＮｂＯ３による置換量ｘを０．４０〜０．５０の範囲としたのは、ＫＮｂＯ３及びＮａＮｂＯ３が同程度の割合で含まれる組成系において最も優れた圧電特性が得られるためである。一方、ｘが０．４０よりも小さいと磁器の焼結性が極端に悪くなり、また、０．５０よりも大きいと圧電特性が著しく低下してしまうことから、焼結性が良好であり、かつ、圧電特性の良好な圧電磁器を得るという観点から、ｘは０．４０〜０．５０の範囲とすることが望ましい。 In the above-described configuration, it was in the range of 0.40 to 0.50 of the substitution amount x by NaNbO 3, since the best piezoelectric properties in the composition system of KNbO 3 and NaNbO 3 is contained at a rate comparable to obtain It is. On the other hand, if x is less than 0.40, the sinterability of the porcelain is extremely deteriorated, and if it is more than 0.50, the piezoelectric properties are remarkably deteriorated. In addition, from the viewpoint of obtaining a piezoelectric ceramic with good piezoelectric characteristics, x is preferably in the range of 0.40 to 0.50.
前記構成において、ＣａＴｉＯ３による置換量ｙを０．０３〜０．１１の範囲としたのは、磁器の焼結性が良好であるからである。ｙが０．０３よりも小さい場合は、磁器の焼結性が低下し、緻密な焼結体が得られない。また、ｙが０．１１よりも大きい場合は、圧電磁器のキュリー温度が１８０℃以下となって、圧電磁器の耐熱性が低下するので実用に供さなくなる。 The reason why the substitution amount y with CaTiO 3 is set in the range of 0.03 to 0.11 in the above configuration is that the sinterability of the porcelain is good. When y is smaller than 0.03, the sinterability of the porcelain is lowered and a dense sintered body cannot be obtained. On the other hand, when y is larger than 0.11, the Curie temperature of the piezoelectric ceramic becomes 180 ° C. or lower, and the heat resistance of the piezoelectric ceramic is lowered, so that it is not practically used.
前記構成において、ＭｎＣＯ３を１ｗｔ％以下の範囲としたのは、磁器の焼結性が向上するとともに、機械的品質係数Ｑｍが増加するためである。また、ＭｎＣＯ３が１ｗｔ％よりも多い場合は、磁器の焼結性が低下し、緻密な焼結体が得られない。 The reason why MnCO 3 is in the range of 1 wt% or less in the above configuration is that the sinterability of the porcelain is improved and the mechanical quality factor Qm is increased. Also, if MnCO 3 is greater than 1 wt%, the reduced sintering of the porcelain, not dense sintered body is obtained.
前記構成において、Ｌａ２Ｏ３を１ｗｔ％以下の範囲としたのは、磁器の焼結性が向上するとともに、分極処理されやすくなるためである。また、Ｌａ２Ｏ３が１ｗｔ％よりも多い場合は、磁器の焼結性が低下し、緻密な焼結体が得られない。 The reason why La 2 O 3 is in the range of 1 wt% or less in the above configuration is that the sinterability of the porcelain is improved and the polarization treatment is easily performed. Moreover, La case 2 O 3 is greater than 1 wt%, the reduced sintering of the porcelain, not dense sintered body is obtained.
本発明の圧電磁器は、例えば、次のようにして製造することができる。まず、原料粉末として、Ｋ２ＣＯ３，Ｎａ２ＣＯ３，Ｌｉ２ＣＯ３，ＣａＣＯ３，Ｎｂ２Ｏ５，ＴｉＯ２，及びＭｎＣＯ３，Ｌａ２Ｏ３のうちのいずれかの原料を用いて、これらを予め所望の組成になるよう秤量し、例えば、これをＺｒＯ２ボールを用いた湿式方式で混合する。次に、この混合粉体を７００〜９００℃で仮焼成し、所望の組成の合成粉体を得る。 The piezoelectric ceramic of the present invention can be manufactured as follows, for example. First, as a raw material powder, any one of K 2 CO 3 , Na 2 CO 3 , Li 2 CO 3 , CaCO 3 , Nb 2 O 5 , TiO 2 , and MnCO 3 , La 2 O 3 is used. These are weighed in advance so as to have a desired composition, and, for example, they are mixed by a wet method using ZrO 2 balls. Next, the mixed powder is temporarily fired at 700 to 900 ° C. to obtain a synthetic powder having a desired composition.
得られた合成粉体については、例えば、ＺｒＯ２ボールを用いて湿式粉砕し、乾燥させ、この混合粉末に有機バインダーを加え、金型プレス、静水圧プレス等により所望の形状に成形した後、大気中、１０８０〜１２００℃で３〜５時間焼成して磁器を得ることができる。 About the obtained synthetic powder, for example, after wet-grinding using ZrO 2 balls and drying, an organic binder is added to this mixed powder, and after molding into a desired shape by a die press, an isostatic press, etc. Porcelain can be obtained by firing at 1080 to 1200 ° C. for 3 to 5 hours in the air.
使用する各原料粉末は、酸化物だけでなく、炭酸塩、酢酸塩又は有機金属などの化合物のいずれであっても、焼成などの熱処理プロセスによって酸化物になるものであれば何ら差し支えなく、適宜の原料を使用することができる。 Each raw material powder to be used is not limited to oxides, and any of compounds such as carbonates, acetates, or organic metals can be used as long as they become oxides by a heat treatment process such as firing. Ingredients can be used.
これらの原料粉末は、上記組成式の組成範囲になるように任意の手段で秤量し、これらを混合し、混合粉末とするが、その場合、材料の混合方式としては、例えば、乾式混合、湿式混合が例示され、粉砕方法としては、例えば、乾式粉砕法、湿式粉砕法が例示され、成型方法としては、例えば、乾式プレス法、冷間等方プレス法（ＣＩＰ）等が例示され、また、加熱処理時の状態としては、大気中や、窒素、アルゴン、酸素フロー中などの雰囲気中での加熱処理が例示される。しかし、これらに制限されるものではない。 These raw material powders are weighed by any means so as to be within the composition range of the above composition formula, and mixed to obtain a mixed powder. In this case, as a mixing method of the materials, for example, dry mixing, wet processing, etc. Mixing is exemplified, and examples of the pulverization method include dry pulverization method and wet pulverization method. Examples of the molding method include dry press method and cold isotropic press method (CIP). Examples of the state during the heat treatment include heat treatment in the atmosphere or in an atmosphere such as nitrogen, argon, or oxygen flow. However, it is not limited to these.
本発明のニオブ酸アルカリ系圧電磁器組成物は、上記製造プロセスを採用することにより、優れた圧電特性を有する圧電磁器が得られる、焼結性が良好である、機械的品質係数が増加する、緻密な焼結体が得られる、分極処理されやすい等の利点を有する。 The alkali niobate-based piezoelectric ceramic composition of the present invention is obtained by adopting the above manufacturing process, and a piezoelectric ceramic having excellent piezoelectric characteristics is obtained, the sinterability is good, and the mechanical quality factor is increased. There are advantages such that a dense sintered body can be obtained and polarization treatment is easy.
従来のＫＮｂＯ３−ＮａＮｂＯ３を主成分とするニオブ酸系アルカリ圧電磁器組成物では、室温〜１００℃付近に相転移点が存在するため、圧電素子の使用範囲において圧電特性の著しい変化が生じ、そのことがニオブ酸系アルカリ圧電磁器の製品化の障害となっていた。これに対して、本発明では、上記ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の組成の一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時置換することで圧電磁器の相転移点を室温以下に降下させることが可能であり、これにより、圧電素子の使用温度範囲において、圧電特性の著しい変化の生じない、実用化可能な特性を有する新規ニオブ酸アルカリ系圧電磁器組成物を提供することを実現するものである。 In the conventional niobic acid-based alkaline piezoelectric ceramic composition mainly composed of KNbO 3 —NaNbO 3 , a phase transition point exists in the vicinity of room temperature to 100 ° C., so that a significant change in piezoelectric characteristics occurs in the usage range of the piezoelectric element, This has been an obstacle to the commercialization of niobate-based alkaline piezoelectric ceramics. On the other hand, in the present invention, the phase transition point of the piezoelectric ceramic is lowered below room temperature by simultaneously replacing part of the composition of the piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 with LiNbO 3 and CaTiO 3. Accordingly, it is possible to provide a novel alkali niobate piezoelectric ceramic composition having a practically usable characteristic that does not cause a significant change in the piezoelectric characteristic in the operating temperature range of the piezoelectric element. Is.
本発明により、次のような効果が奏される。
（１）本発明の圧電磁器では、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器で実用化の問題となっていた室温〜１００℃付近の相転移点を、圧電磁器の組成の一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時に置換することによって、室温以下まで降下させることが実現可能である。
（２）本発明の圧電磁器を使用することによって、自然環境に優しい、鉛を含まない実用的なニオブ系圧電素子の製造が可能である。
（３）相転移温度を室温以下に低下させたニオブ酸アルカリ系の圧電磁器を提供することができる。
（４）高い電気機械結合係数及び高い圧電歪定数を示し、しかも、相転移点が室温以下である新規圧電磁器組成物を提供することができる。
（５）ニオブ系圧電磁器の、実用化可能な新規組成物からなる圧電材料を製造し、提供することができる。
The following effects are exhibited by the present invention.
(1) In the piezoelectric ceramic according to the present invention, a phase transition point from room temperature to around 100 ° C., which has been a practical problem in a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 , is obtained by using a part of the composition of the piezoelectric ceramic. By simultaneously substituting with LiNbO 3 and CaTiO 3 , it is possible to lower the temperature to below room temperature.
(2) By using the piezoelectric ceramic of the present invention, it is possible to manufacture a practical niobium-based piezoelectric element that is friendly to the natural environment and does not contain lead.
(3) An alkali niobate piezoelectric ceramic having a phase transition temperature lowered to room temperature or lower can be provided.
(4) A novel piezoelectric ceramic composition that exhibits a high electromechanical coupling coefficient and a high piezoelectric strain constant and that has a phase transition point of room temperature or lower can be provided.
(5) It is possible to manufacture and provide a piezoelectric material made of a novel composition that can be put into practical use for a niobium piezoelectric ceramic.
次に、本発明を実施例に基づいて具体的に説明するが、本発明は、これに限定されるものではない。 Next, the present invention will be specifically described based on examples, but the present invention is not limited thereto.
本実施例では、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の組成の一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時置換した特定組成の４成分系ＫＮ−ＮＮ−ＬＮ−ＣＴ、また、これに副成分として１ｗｔ％ＭｎＣＯ３又はＬａ２Ｏ３を配合したＫＮ−ＮＮ−ＬＮ−ＣＴ＋１ｗｔ％ＭｎＣＯ３、ＫＮ−ＮＮ−ＬＮ−ＣＴ＋１ｗｔ％Ｌａ２Ｏ３を作製し、得られた圧電磁器の特性を評価した。 In this example, a quaternary system KN-NN-LN-CT having a specific composition in which a part of the composition of a piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 is simultaneously substituted with LiNbO 3 and CaTiO 3 , KN-NN-LN-CT + 1 wt% MnCO 3 and KN-NN-LN-CT + 1 wt% La 2 O 3 containing 1 wt% MnCO 3 or La 2 O 3 as subcomponents were prepared, and the characteristics of the obtained piezoelectric ceramic were evaluated.
出発原料として、Ｋ２ＣＯ３，Ｎａ２ＣＯ３，Ｌｉ２ＣＯ３，ＣａＣＯ３，Ｎｂ２Ｏ５，ＴｉＯ２ 及びＭｎＣＯ３，Ｌａ２Ｏ３の原料粉末を使用した。これらの原料粉末を所定の組成割合に配合し、これらの原料粉末に、エタノールを加え、直径１０ｍｍのＺｒＯ２ボールを用いて２４時間湿式混合した後、乾燥機で十分に乾燥させた。この混合粉体を９００℃で３時間仮焼して仮焼粉体を作製した。 As starting materials, raw material powders of K 2 CO 3 , Na 2 CO 3 , Li 2 CO 3 , CaCO 3 , Nb 2 O 5 , TiO 2 and MnCO 3 , La 2 O 3 were used. These raw material powders were blended at a predetermined composition ratio, ethanol was added to these raw material powders, wet-mixed for 24 hours using ZrO 2 balls having a diameter of 10 mm, and then sufficiently dried with a dryer. This mixed powder was calcined at 900 ° C. for 3 hours to prepare a calcined powder.
これらの仮焼粉体に、エタノールを加え、直径１０ｍｍのＺｒＯ２ボールを用いて２時間ボールミル粉砕を行った。 Ethanol was added to these calcined powders, and ball milling was performed for 2 hours using ZrO 2 balls having a diameter of 10 mm.
ボールミル粉砕した仮焼粉体については、乾燥機で十分に乾燥させた後、有機バインダーを混合して造粒し、得られた粉末を２００ＭＰａの圧力で直径１７ｍｍ、厚さ１．５ｍｍの円板に成形した後、この成形体を大気中において１０８０〜１２００℃で３時間焼成して磁器を得た。その後、磁器をラップ盤を用いて厚さ１ｍｍに研磨した。 The calcined powder that has been pulverized by ball mill is sufficiently dried with a dryer, and then mixed with an organic binder and granulated. The resulting powder is a disc having a diameter of 17 mm and a thickness of 1.5 mm at a pressure of 200 MPa. Then, this molded body was fired in the atmosphere at 1,080 to 1,200 ° C. for 3 hours to obtain a porcelain. Thereafter, the porcelain was polished to a thickness of 1 mm using a lapping machine.
研磨した試料については、上下面に銀ペーストを塗布し、７００℃で３０分間熱処理して銀電極を形成した。その後、試料を１００℃のシリコンオイル中で５ｋＶ／ｍｍの直流電界を１０分間印加して分極処理を行った。 For the polished sample, a silver paste was applied to the upper and lower surfaces and heat treated at 700 ° C. for 30 minutes to form a silver electrode. Thereafter, the sample was subjected to polarization treatment by applying a DC electric field of 5 kV / mm for 10 minutes in 100 ° C. silicone oil.
分極処理した試料については、室温で一晩放置することによって圧電特性を安定化させた後、静電容量、共振・反共振周波数をインピーダンスアナライザを用いて測定し、比誘電率、電気機械結合係数を求めた。また、ｄ３３メーターを用いて試料の圧電歪ｄ３３定数を測定した。更に、静電容量の温度変化を測定することによって試料のキュリー温度及び第二相転移温度を求めた。図１に、室温以上で第二相転移温度を示す従来のニオブ酸系圧電磁器の誘電特性図を、また、図２に、本発明によって作製した圧電磁器の誘電特性図をそれぞれ示す。ここで、第二相転移温度とは斜方晶から正方晶に試料の結晶構造が変化する温度を意味する。作製した圧電磁器の組成、焼結温度、得られた圧電磁器の第二相転移温度、圧電歪ｄ３３定数（ｐｍ／ｖ）、電気機械結合係数（ｋｐ）、及び分極後の位相の値を表１に示した。 For a polarized sample, the capacitance and resonance / anti-resonance frequency were measured using an impedance analyzer after standing overnight at room temperature to stabilize the piezoelectric characteristics, and the relative dielectric constant and electromechanical coupling coefficient were measured. Asked. Further, the piezoelectric strain d33 constant of the sample was measured using a d33 meter. Furthermore, the Curie temperature and the second phase transition temperature of the sample were determined by measuring the temperature change of the capacitance. FIG. 1 shows a dielectric characteristic diagram of a conventional niobic acid type piezoelectric ceramic showing a second phase transition temperature at room temperature or higher, and FIG. 2 shows a dielectric characteristic diagram of a piezoelectric ceramic produced by the present invention. Here, the second phase transition temperature means a temperature at which the crystal structure of the sample changes from orthorhombic to tetragonal. The composition of the produced piezoelectric ceramic, the sintering temperature, the second phase transition temperature of the obtained piezoelectric ceramic, the piezoelectric strain d33 constant (pm / v), the electromechanical coupling coefficient (kp), and the phase value after polarization are shown. It was shown in 1.
その結果、１０８０〜１２００℃の焼結で焼結不可の試料、２０℃ないし４０℃に相転移点がある試料については、評価を中止した。そして、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器の組成において、その一部をＬｉＮｂＯ３及びＣａＴｉＯ３で同時置換し、また、副成分としてＭｎＣＯ３又はＬａ２Ｏ３を含む特定の組成範囲の組成物では、圧電磁器の相転移温度が温室以下に低下することが分かった。 As a result, the evaluation was stopped for samples that could not be sintered by sintering at 1,080 to 1,200 ° C. and samples that had a phase transition point at 20 ° C. to 40 ° C. Then, in the composition of the piezoelectric ceramic mainly composed of KNbO 3 -NaNbO 3, simultaneously replacing a part in LiNbO 3 and CaTiO 3, also specific composition range including MnCO 3 or La 2 O 3 as an auxiliary component It was found that the phase transition temperature of the piezoelectric ceramic is lowered below the greenhouse in the composition of
そして、これらの実験及びその結果から、上記４成分系の圧電磁器組成物において、モル比による組成式を、次の式；
（１−ｘ−ｙ）ＫＮｂＯ３＋ｘＮａＮｂＯ３＋ｙ（ＬｉＮｂＯ３＋ＣａＴｉＯ３）
とした時、ｘ及びｙの値が、０．４０≦ｘ≦０．５０、０．０３≦ｙ≦０．１１である場合に、相転移室温が温室以下で、優れた圧電性能を有する圧電磁器を作製できることが実証された。
Then, from these experiments and the results thereof, in the above four-component piezoelectric ceramic composition, the composition formula by molar ratio is expressed by the following formula:
(1-xy) KNbO 3 + xNaNbO 3 + y (LiNbO 3 + CaTiO 3 )
When the values of x and y are 0.40 ≦ x ≦ 0.50 and 0.03 ≦ y ≦ 0.11, the phase transition room temperature is below the greenhouse and the piezoelectric has excellent piezoelectric performance. It has been demonstrated that porcelain can be made.
以上詳述したように、本発明は、ニオブ酸アルカリ系圧電磁器組成物に係るものであり、本発明により、従来、ＫＮｂＯ３−ＮａＮｂＯ３を主成分とする圧電磁器で実用化の障害として問題となっていた室温〜１００℃付近の相転移点を、室温以下まで降下させた新規ニオブ酸系圧電磁器組成物を作製し、提供することができる。本発明は、自然環境に優しい、鉛を含まない圧電磁器組成物を提供するものであり、それにより、鉛を含まない環境低負荷型の実用化可能なニオブ系圧電素子及び該圧電素子を利用した圧電部材を製造し、提供することを可能にするものである。本発明は、ニオブ酸系圧電磁器の実用化可能な新規組成物及びその製品に関する新技術・新製品を提供するものとして有用である。 As described above in detail, the present invention relates to an alkali niobate-based piezoelectric ceramic composition, and according to the present invention, a conventional piezoelectric ceramic mainly composed of KNbO 3 —NaNbO 3 has a problem as an obstacle to practical use. Thus, a novel niobic acid piezoelectric ceramic composition in which the phase transition point from room temperature to around 100 ° C. is lowered to room temperature or lower can be prepared and provided. The present invention provides a piezoelectric ceramic composition that does not contain lead and is friendly to the natural environment, and thereby uses a niobium-type piezoelectric element that does not contain lead and that can be put to practical use, and that uses the piezoelectric element. It is possible to manufacture and provide a piezoelectric member. INDUSTRIAL APPLICABILITY The present invention is useful as a new composition for practical application of a niobic acid piezoelectric ceramic and a new technology / new product related to the product.
Claims (8)
（１−ｘ−ｙ）ＫＮｂＯ３＋ｘＮａＮｂＯ３＋ｙ（ＬｉＮｂＯ３＋ＣａＴｉＯ３）
とした時、ｘ及びｙの値が、０．４０≦ｘ≦０．５０、０．０３≦ｙ≦０．１１を満たす、請求項１に記載の圧電磁器。 A piezoelectric ceramic mainly composed of a perovskite compound mainly composed of Na, K, Li, Ca, Nb, and Ti.
(1-xy) KNbO 3 + xNaNbO 3 + y (LiNbO 3 + CaTiO 3 )
The piezoelectric ceramic according to claim 1, wherein the values of x and y satisfy 0.40 ≦ x ≦ 0.50 and 0.03 ≦ y ≦ 0.11.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007055867A (en) * | 2005-08-26 | 2007-03-08 | National Institute Of Advanced Industrial & Technology | Piezoelectric ceramic composition |
| WO2008108355A1 (en) | 2007-03-06 | 2008-09-12 | Swcc Showa Cable Systems Co., Ltd. | Resin composition for insulation, and wire/cable using the same |
| JP2010195624A (en) * | 2009-02-25 | 2010-09-09 | Kyocera Corp | Piezoelectric ceramic and piezoelectric element |
| JP2011518757A (en) * | 2008-04-30 | 2011-06-30 | エプコス アクチエンゲゼルシャフト | Ceramic material, method for producing ceramic material, and component made of ceramic material |
| WO2012015016A1 (en) * | 2010-07-30 | 2012-02-02 | 旭硝子株式会社 | Sputtering target and process for production thereof |
| US20150137667A1 (en) * | 2013-11-15 | 2015-05-21 | AAC Technologies Pte. Ltd. | Ceramic material, sinter, ceramic device, piezoelectricity ceramic bimorph and gluing method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5047193A (en) * | 1973-08-15 | 1975-04-26 | ||
| JPH11228227A (en) * | 1998-02-18 | 1999-08-24 | Murata Mfg Co Ltd | Piezoelectric ceramic composition |
-
2005
- 2005-08-26 JP JP2005245197A patent/JP2007055864A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5047193A (en) * | 1973-08-15 | 1975-04-26 | ||
| JPH11228227A (en) * | 1998-02-18 | 1999-08-24 | Murata Mfg Co Ltd | Piezoelectric ceramic composition |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007055867A (en) * | 2005-08-26 | 2007-03-08 | National Institute Of Advanced Industrial & Technology | Piezoelectric ceramic composition |
| WO2008108355A1 (en) | 2007-03-06 | 2008-09-12 | Swcc Showa Cable Systems Co., Ltd. | Resin composition for insulation, and wire/cable using the same |
| JP2011518757A (en) * | 2008-04-30 | 2011-06-30 | エプコス アクチエンゲゼルシャフト | Ceramic material, method for producing ceramic material, and component made of ceramic material |
| US8786167B2 (en) | 2008-04-30 | 2014-07-22 | Epcos Ag | Ceramic material, method for the production of the ceramic material and component comprising the ceramic material |
| JP2010195624A (en) * | 2009-02-25 | 2010-09-09 | Kyocera Corp | Piezoelectric ceramic and piezoelectric element |
| WO2012015016A1 (en) * | 2010-07-30 | 2012-02-02 | 旭硝子株式会社 | Sputtering target and process for production thereof |
| US20150137667A1 (en) * | 2013-11-15 | 2015-05-21 | AAC Technologies Pte. Ltd. | Ceramic material, sinter, ceramic device, piezoelectricity ceramic bimorph and gluing method thereof |
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