降低Pb(Mn1/3Nb2/3)O3燒結溫度之研究

The Study of Pb(Mn1/3Nb2/3)O3-PZ-PT with lower sintering temperature

陳智彥(Chih-Yen Chen)

指導教授 ： 林和龍 ； 胡毅

大同大學/工程學院/材料工程學系所/博士(2006年)

摘要

電子陶瓷大抵為多晶且多成分合成的氧化物，其物性的變化則需要同時從微觀組織、化學組成、化學均勻性等方面來了解。溶膠-凝膠等化學方法製備粉體雖然均勻且性質極佳，但所需的製備時間與成本極高，並不符合目前社會的經濟效應，反觀傳統的固態反應法在製備粉體並無法得到如化學法同樣的性質，不過其過程極為簡易且產量極大，因此成為最有競爭力的製備方式。
由於電子陶瓷具有其獨特且優異的特性，因此在電子工業上被大量的應用。由於壓電陶瓷具有機電轉換的特性，利用它所製成的產品種類相當多，如瓦斯爐的點火器，揚聲器，超音波震盪器，驅動器，超音波馬達，都是運用機械能與電能的互換特性所製成。此外還可以製成壓電變壓器與濾波器，應用相當廣泛，主要應用的材料是PZT、PMN-PT等材料。
在元件的製程中，高溫燒結對於製造成本部分會大幅度的增加，其中電極的成本為最主要的部分。此外，高溫燒結對於能源部分的損耗亦為可觀。現今人們對於環保問題日益重視，重金屬物質與揮發性的污染需極力避免，但高溫燒結(>1200℃)會導致大量的鉛揮發而產生環境的污染。若降低燒結溫度可以避免鉛揮發所造成環境污染以及能源損耗的情況，而電極的取得也較為低廉。
本研究分為兩大方式降低燒結溫度，首先是利用煆燒溫度、燒結溫度及PbO過量程度改變來達成，由結果可知在Pb(Mn1/3Nb2/3)O3-PbZrO3-PbTiO3添加2wt%的PbO在1200oC煆燒3小時並在1050oC燒結3小時有最佳的壓電特性，此時Qm可達2101且kp亦有0.626。其二係利用真空燒結的方式降低燒結溫度。由結果可知燒結過程由室溫維持10mtorr的真空度升溫至800oC破真空並持溫1小時，再升溫至1050oC持溫1小時有最佳的壓電特性，Qm可高達2100而kp亦可維持0.610。以上的結果皆能有效的將低原先的燒結溫度約200oC，這對於產品成本的降低有極大的助益，並且可大幅的降低環境污染所造成的衝擊。

關鍵字

電子陶瓷

並列摘要

Ferroelectric ceramics have long been used as sensors and actuators due to their piezoelectric properties [1,2]. They are capable of high frequency response and are thus ideal for ultrasonic applications. However, the strain available is limited, and clever mechanical devices have been invented to amplify the strain. Recently, attention has focused on developing materials capable of large strains. Coupled with the recent interest in ferroelectric memories [3,4], the last decade has been one of significant advances. New materials have been developed and systematic attempts to manipulate domains have been pursued. New experimental methods have probed the material at the atomistic and domain scales. Significant advances have been made in the theoretical understanding of the origins of ferroelectricity, the nature of domain patterns and the overall behavior of materials. Modern methods of synthesis with controlled texture and composition have opened the possibility of exploiting the inherent microscopic features of these materials. This paper reviews the recent theoretical and experimental advances, and comment on opportunities and challenges for the future. Rather than attempt a comprehensive survey, we provide some snapshots of the recent developments. A variety of materials have been found to exhibit ferroelectricity [5,6,7].
The best piezoelectric property is given for the sample venting 800oC for 1 hour and sintering at 1050oC for 1 hour at 10mtorr. The value of Qm can be reached to 2100 and kp can maintain 0.610. The sintering temperature is apparently lower than the traditional sintering. The piezoelectric of Qm and kp are also improved.

並列關鍵字

PZT

參考文獻

1. W. G. Cady. Piezoelectricity, pp. 1-20. McGraw-Hill. New York, 1946.

2. Bernard Jaffe, William. R. Cook, Hans Jaffe, “Piezoelectric Ceramics”, London 1971.

4. Carl, K. & Hardtl, K. H., Phys. Status Solid (a), 8 (1971) 218.

5. Isupov, V. A., Solid State Commun., 17 (1975) 1331.

7. Ari-Gur, P. & Benguigui, L., Solid State Commun., 24 (1977) 769.