低溫燒結六方晶鈦酸鋇之微波介電特性

Microwave Dielectric Properties of Low-Temperature Sintered Hexagonal Barium Titanate

黄心嫻(Hsin-sian Huang)

指導教授 ： 王錫福

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00574

摘要

為了因應低溫共燒陶瓷（LTCC）的快速發展，許多具良好微波介電性質之高溫燒結的介電材料，發展出利用液相燒結之技術在不影響微波性質之條件下降低其燒結溫度。而近年來發現經受體摻雜之高溫相六方晶鈦酸鋇（h-BaTiO3）陶瓷具有微波介電特性，其中授體摻雜 Mn元素之六方晶鈦酸鋇Ba(Ti1-xMnx)O3，當 x=0.15時在1150℃持溫煆燒4小時即可獲得純相六方晶鈦酸鋇，具有可應用於低溫共燒陶瓷之可能性；而當x=0.5時，六方晶鈦酸鋇Ba(Ti1-xMnx)O3陶瓷具有滿足介電共振器之微波介電條件，因此以此兩種化合物為主題進行低溫燒結研究。
本研究主要是利用傳統固態反應法，將BaCO3、TiO2 、Mn3O4混和後，煆燒成六方晶鈦酸鋇 Ba(Ti1-xMnx)O3（x=0.15、0.5），再將Ba(Ti1-xMnx)O3 粉末添加不同燒結助劑於以降低高溫相六方晶鈦酸鋇之燒結溫度，並且維持高的介電常數（εr）、品質因數（Q×f）以及降低共振頻率溫度係數（τf）。本研究將針對緻密化行為、微結構變化及微波介電性質作探討，結果發現添加Bi2O3、Li2CO3之 Ba(Ti1-xMnx)O3可以形成液相燒結，有效降低六方晶鈦酸鋇之燒結溫度約 200℃~ 300℃，並可獲得不錯的微波介電性質。其中，最佳微波介電性質出現在添加5wt% Bi2O3之 Ba(Ti0.5Mn0.5)O3，燒結溫度1250℃時，可得到接近於的共振頻率溫度係數，其介電性質為εr = 30.1、Q×f = 4,340 GHz及τf = -2.4 ppm/℃。

關鍵字

鈦酸鋇 ； 六方晶 ； 微波介電性質 ； 低溫燒結

並列摘要

For the tendency of LTCC technique, how to maintain the best microwave dielectric properties in low temperature sintering became a critical issue, so the development of microwave dielectric ceramics sintered with fluxes were discussed. Recently, the microwave dielectric properties of high temperature sintering hexagonal Barium Titanate（BaTiO3）have been reported. And hexagonal Barium Titanate （BaTiO3）incorporate with Mn dopant (Ba(Ti1-xMnx)O3) could been a single hexagonal phase when x=0.15 and calcined at 1150 ℃ for 4 h, and the Ba(Ti1-xMnx)O3 have big potential used in LTCC technique. Otherwise, there are best microwave dielectric properties when x=0.5 have been reported as potential candidates used in microwave dielectric resonators. So, the properties of Ba(Ti1-xMnx)O3 when the compositions x=0.15 and x=0.5 were investigated.
The Ba(Ti1-xMnx)O3 ceramics were synthesized by traditional solid-state reaction with the raw powders of BaCO3, TiO2, and Mn3O4, and then mix with different aids to reduce the sintering temperature and still retain the best microwave dielectric properties. So, the microstructures and properties of the Ba(Ti1-xMnx)O3 samples are analyzed by measuring dielectric parameters, XRD and SEM. The results show that Bi2O3 and Li2CO3 can be sintered with fluxes, and then effectively reduce the sintering temperature about 200℃~300℃, in the same time keep the microwave dielectric properties. In this study, the best microwave dielectric properties were obtained for the 6h-Ba(Ti0.5Mn0.5)O3 with the additions of 5 wt% Bi2O3 sintered at 1250℃（εr = 0.1, Q×f = 4,340 GHz及 τf = -2.4 ppm/℃）.

並列關鍵字

BaTiO3 ； Hexagonal ； Microwave Dielectric Properties ； Low Temperature Sintering

參考文獻

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