氧化鋯含量對莫來石/氧化鋯複合材料之電性影響

Abstract

本實驗利用將粉末分散後用熱壓法壓製出各種不同氧化鋯含量之mulite/zirconia陶瓷複合材料，利用AC Impedance量測在300℃~1300℃的離子導電率，在用XRD鑑定相別，SEM做微觀結構之觀察與利用Z-view軟體所Fitting出之等效電路做交互驗證已著實確定各等效電路之意義，並繪畫出各試片相對應等效電路之Arrhenius圖求其Q(活化能)值。研究結果顯示，mullite試片的活化能值約為0.63(eV)、MZY10與MZY20皆有轉折溫度約為700℃其低溫活化能值為0.57(eV)、0.68(eV)，高溫活化能值為0.93(eV)、1.15(eV)，MZY30 活化能值為0.98(eV)，MZY40活化能值為0.85(eV)。將整體試片活化能值與各相對應等效電路活化能值作比較可推測出在各個不同的mullite/zirconia陶瓷複合材料在不同溫度下的可能離子移動路徑。再利用活化能值與Rzirconia/Rall分佈曲線推測出臨界體積分率為30％。

The effects of different zirconia content on ionic conductivity and microstructure in mullite/zirconia composite are studied using AC Impedance, SEM and XRD. The activity energy of mullite is about 0.63(eV) at 300oC~1300oC. The MZY10 and MZY20 have a gradual transition in a temperature about 700oC , however the temperature is smaller than 700oC, its activity energies are 0.57(eV)and 0.68(eV). When the temperature is above 700oC, its activity energies are 0.93(eV) and 1.15(eV). The activity energy of MZY30 is 0.98(eV). The activity energy of MZY40 is 0.82(eV). Compare the activity energies of samples with the activity energies of the related equal circuit, we could presume that the ionic transport way in samples. Using the diagram of Rzirconia/Rall vs. ZrO2 could predict the critical volume at 30 vol%~40 vol%