In-Bi-Tl三元系液体合金中成分的活度测定

CALCULATION OF THERMODYNAMIC PROPERTIES OF In-Bi-Tl TERNARY ALLOYS

用ZrO_2固体电解质组成氧浓差电池:(-)Re,In,In_2O_3|ZrO_2(Y_2O_3)|In-Bi-Tl,In_2O_3,Re(+),在973—1223K的温变范围内测定了In-Bi-Tl三元系中含Tl量较少的两个mol比(N_(Bi)/N_(Tl))一定的拟二元系合金中In的活度,据实验结果求得合金的过剩自由能。使用作者曾提出的计算式及有关各二元系热力学数据计算了合金中In的活度及过剩自由能。计算值与实验值相当一致。此三元系合金的过剩自由能除在In-Tl二元系相近组成以外都呈负值,极小值在Bi-Tl二元系上。

The excess molar free energy of the In-Bi-Tl ternary alloys at hightemperature has been calculated from the data of the three related binary systemsby means of the equation presented by the authors previously. The activities of Inin two pseudo-binary systems of fixed N_(Bi)/N_(Tl) molar fraction ratio have been deter-mined by the EMF method using ZrO_2 solid electrolyte over the temperature rangeof 973--1223K. The thermodynamic properties of the ternary alloys determined fromthe experimental data agree well with the calculated values. The excess molar freeenergies of the ternary alloys are negative in almost all compositions except thosenear the In-Tl side and become negatively larger as the compositions approach theBi-Tl side.