HR-TEM and FIB-SEM characterization of formation of eutectic-like structure from amorphous GdAlO_3-Al_2O_3 system  

作　　者：Y.H.HAN Y.HARADA J.F.SHACKELFORD Jaehyung LEE K.KAKEGAWA 

机构地区：[1]School of Materials Science and Engineering,Yeungnam University [2]Department of Chemical Engineering and Materials Science,University of California at Davis [3]Graduate School of Engineering,Chiba University

出　　处：《中国有色金属学会会刊：英文版》2012年第S3期579-584,共6页Transactions of Nonferrous Metals Society of China

基　　金：part of the study under the "Human Resource Development Center for Economic Region Leading Industry" Project;supported by the Ministry of Education,Science & Technology(MEST);by the National Research Foundation of Korea(NRF)

摘　　要：The crystallization process of the eutectic composition of GdAlO_3-Al_2O_3 from the amorphous phase prepared by rapid-quenching of melt that leads to the formation of a cantaloupe skin-like microstructure was investigated using focused ion-beam scanning electron microscopy (FIB-SEM) and high-resolution transmission electron microscopy (HR-TEM).The amorphous films were heat-treated at temperatures between 1000 °C and 1500 °C for up to 30min to form the eutectic phases of GdAlO_3 and Al_2O_3.The GdAlO_3 and Al_2O_3 crystal phases that formed from the amorphous phase were identified by FIB-SEM and HR-TEM.Both components began to crystallize and grow from the amorphous phase separately at different temperatures.The formation process of these crystal phases was different from that of the ordinary eutectic microstructure solidified from the GdAlO_3-Al_2O_3 system.Therefore,the observed structure is termed "eutectic-like" for distinction.The microstructures formed from the amorphous phases at sufficiently high temperatures consisted of ultra-fine microstructures of individually crystallized components and were similar to ordinary eutectic microstructures.By heat-treating the amorphous films at 1500 °C for either 2 min,8min or 30min,the ultra-fine components of GdAlO_3 and Al_2O_3 were found to crystallize following a eutectic-like stage after 8min of heat treatment.The crystallization process of the eutectic composition of GdAlO₃-Al₂O₃ from the amorphous phase prepared by rapid-quenching of melt that leads to the formation of a cantaloupe skin-like microstructure was investigated using focused ion-beam scanning electron microscopy （FIB-SEM） and high-resolution transmission electron microscopy （HR-TEM）.The amorphous films were heat-treated at temperatures between 1000 °C and 1500 °C for up to 30min to form the eutectic phases of GdAlO₃ and Al₂O₃.The GdAlO₃ and Al₂O₃ crystal phases that formed from the amorphous phase were identified by FIB-SEM and HR-TEM.Both components began to crystallize and grow from the amorphous phase separately at different temperatures.The formation process of these crystal phases was different from that of the ordinary eutectic microstructure solidified from the GdAlO₃-Al₂O₃ system.Therefore,the observed structure is termed "eutectic-like" for distinction.The microstructures formed from the amorphous phases at sufficiently high temperatures consisted of ultra-fine microstructures of individually crystallized components and were similar to ordinary eutectic microstructures.By heat-treating the amorphous films at 1500 °C for either 2 min,8min or 30min,the ultra-fine components of GdAlO₃ and Al₂O₃ were found to crystallize following a eutectic-like stage after 8min of heat treatment.

关 键 词：eutectic AMORPHOUS GdAlO3-Al2O3 eutectic-like HR-TEM FIB-SEM Crystallization 

分 类 号：O614.31[理学—无机化学]