電化電解池方法於砷化鎵、砷化金因與砷化鎵金因液相溶液之熱力學性質之研究

Abstract

本文主要是以利用CSZ及YSZ為固態電解質之電化學電池作砷化鎵、砷化鈉及InXGa1-xAS等材料之混合物溶液的熱力性質分析，由電解池之電位測量可由下式求得砷化鎵及InXGa1-xAS混合物溶液中鎵之活性，同時另一混合物溶液神化銦中之銦的活性也可求得 aGal=exp(-3EF/RT) 結果顯示，二個二元系統之活性測量均呈現與理想溶液成負偏差，而在三元系統，InxGal-xAS混合物溶液中鎵之活性則與理想溶液成正偏差。本文另以NRTL與Simple solution數學模式所預測之熱力性質與實驗結果比較。結果二個二元系統理論值均與實驗值相當吻合，在三元系統中，模式所預測之活性也與實驗值吻合，但模式所預測之過量自由能則略高於實驗值。另外由SimpIe solution數學模式所預測之二元相圖與其他作者所發表之實驗值相當吻合，而預測之三元相圖則與Nakajima[33，34]發表之InxGal-xAS溶液之相圖相符，但略低於Pollack[22]所發表者。

The activity of Ga in GaAs and InxGal-xAs liquid mixtures, and the activity of In in InAs liquid mixture were measured in the high temperature solid state electrochemical cell using Calcia-stabilized Zirconia and Yttria-stabilized Zirconia as the solid electrolyte. The activity was obtained by the E.M.F measurements and calculated by the following equition: ail=exp(-3EF/RT) i= Ga or In The results of the measurements showed a negative deviation from ideal behaviors in the binary systems and a positive deviation in the ternary system. Excess Gibbs free energy of the ternary mixture was derived from the activity of Ga in the liquid mixture. The NRTL and simple solution models fitted the thermodynamic properties well in the binary and ternary mixtures. At the same filne, the simple solution model was in good agreement with the experimental binary phase diagram reported by other authors and with the ternary phase diagram given by Nakajima [33,34], but a little high solid compositions at constant As mole fraction was obtained than the results reported by Pollack [22] in the liquid and solid InxGal-xAs mixtures.