(1. 三峽大學(xué) 材料與化工學(xué)院 無機非金屬晶態(tài)與能源轉(zhuǎn)換材料重點實驗室，宜昌 443002； 2. 廣西新未來信息產(chǎn)業(yè)股份有限公司，北海 536000)
摘 要: 以Ga2O3摻雜量(質(zhì)量分?jǐn)?shù))為3%的ZnO-Ga2O3混合粉體為原料，采用熱壓燒結(jié)法制備GZO陶瓷。通過XRD、SEM、阿基米德排水法和四探針法對燒結(jié)試樣的物相組成、顯微結(jié)構(gòu)、密度和電阻率等進行分析表征。結(jié)果表明：外加壓力能有效降低GZO陶瓷燒結(jié)致密化溫度；當(dāng)外加壓力為18 MPa時，隨燒結(jié)溫度升高，燒結(jié)體的密度和電導(dǎo)率增大；當(dāng)燒結(jié)溫度達1150 ℃時，燒結(jié)體密度和電導(dǎo)率達到最大值；但當(dāng)燒結(jié)溫度繼續(xù)增大時，由于晶粒粗化和Zn元素揮發(fā)導(dǎo)致試樣中氣孔長大，試樣致密度與導(dǎo)電性呈下降趨勢。此外，ZnO-Ga2O3混合粉體在燒結(jié)溫度較低時(1050 ℃)，Ga2O3與ZnO固相反應(yīng)生成ZnGa2O4立方尖晶石相；隨著燒結(jié)溫度升高，ZnGa2O4將與ZnO繼續(xù)反應(yīng)，生成與ZnO六方纖鋅礦結(jié)構(gòu)呈共格關(guān)系的復(fù)雜化合物ZnxGa2Ox+3，并且化合物化學(xué)式中x值隨著燒結(jié)溫度的升高而增加，化合物晶體結(jié)構(gòu)逐漸接近ZnO六方纖鋅礦結(jié)構(gòu)。
關(guān)鍵字: GZO陶瓷；熱壓燒結(jié)；燒結(jié)溫度；致密化；固相反應(yīng)
（1. Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, College of Materials and Chemical Engineering, China Three Gorges University, Yichang 443002, China; 2. New Future Information Industry Co., Ltd., Beihai 536000, China）
Abstract:Gallium-doped zinc oxide ceramic (GZO) was prepared by hot-pressing using 97% ZnO and 3% Ga2O3 mixture powder as raw materials. The phase structure was measured by X-ray diffraction. The microstructure of ceramic was observed by SEM. The density of ceramic was measured by Archimedes method. The electrical property of ceramic was investigated by four-point probe method. The results show that sintering temperature is reduced effectively by external pressure during sintering. With increasing sintering temperature, the relative density increases and electrical resistivity decreases at 18 MPa. The maximum relative density and the lowest resistivity of ceramic are achieved at 1150 ℃. The density and electrical conductivity deceases as temperature rising above 1150 ℃, due to grain coarsening and Zn volatilization caused by porosity growth. In addition, ZnGa2O4 cubic spinel phase is synthesized by solid-phase reaction of Ga2O3 and ZnO at 1050 ℃. As the temperature further increases, ZnGa2O4 reacts with ZnO to form ZnxGa2Ox+3 which has coherent relation with hexagonal wurtzite structure of ZnO, while x rises with temperature increasing, the structure of the complex compounds become more similar to that of ZnO.
Key words: GZO ceramic; hot-pressing; sintering temperature; densification; solid-phase reaction
