鐠攙雜之含釹銪銩稀土銅氧化物超導體高壓合成與特性之研究

Abstract

本研究利用高壓固態法,合成稀土元素 247 相高溫超導體,並以鐠取代稀 土元素,研究鐠取代對其結構及物性的影響.結果發現:超導臨界溫度隨鐠 含量增加而遞減;晶格體積隨鐠量增加而遞增.此外;本研究亦包含電阻率, 麥斯那效應,常態磁化與磁滯曲線之量測,拉曼光譜,電子順磁共振光譜,掃 描式電子顯微鏡微結構分析以及電子微探針元素分佈分析.樣品之氧含量 除以碘間接滴訂法定量外,並嘗試以 X 光光電子能譜的數據分析,所得結 果與碘滴定法之結果極為相似. This reseach is attempted to investigate the effect of praseody- mium substitution for rare - earth elements the structural andical properties of R2Ba4Cu7O15-d high - temperature superco- nductors.The superconducting transition temperatures decrease upon praseodymium substitution;the dimension of unit cell volum decreases upon praseodymiun substitution. Furthermore, we have also measured the temperature - dependent resistivity,normal - state magnetic susceptibility, magnetic hysterresis curves and Meissner effect. The microstructure andntal distribution of the samples were also investigated. The oxygen contents were determined by using iodometric titration as well as X-ray photoelectron spectrometry.The oxygen contentsermined by both methods were found to be fairly consistent.