Equilibrium Studies of Fe in Alkali Phosphate Glasses
Equilibrium Studies of Fe in Alkali Phosphate Glasses
复制标题
碱金属磷酸盐玻璃中Fe的平衡研究
DOI：
10.1111/j.1151-2916.1975.tb19567.x
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发表时间：
1975
影响因子：
3.9
通讯作者：
D. Lahiri
中科院分区：
文献类型：
--
作者：
R. Majumdar;D. Lahiri
通过在空气中平衡不同温度下的玻璃熔体，研究了Na_2 O-P_2 O_5二元玻璃中Fe ~（2+）-Fe ~（3+）的平衡。计算了4种玻璃的1/2Fe_2O_3 → FeO+1/4O_2反应的焓变（δH）。结果表明：（1）随着玻璃中Na_2 O含量的增加，反应平衡向氧化态移动（log（[Fe ~（2+）]/[Fe ~（3+）]）与碱金属摩尔%呈线性关系）;（2）不同组成玻璃的ΔH值基本相等，但与标准计算值有差异。实验测得的ΔH值与反应FePO 4 →1/3Fe 3（PO 4）2+ 1/6P 2 O 5 +1/4 O2的Δ H值相近，表明在Na 2 O-P2 O 5玻璃中Fe以磷酸盐或多磷酸盐的形式存在。在某些研究的玻璃中，沉淀出一种淡粉色固体;其X射线衍射图表明其主要成分是结晶Na 2Fe 111 P3 O 10。
The Fe2+-Fe3+ equilibrium in binary Na2O-P2O5, glasses was studied by equilibrating glass melts at different temperatures in air. The enthalpy change (δH) of the reaction 1/2Fe2O3⇌FeO+1/4O2 was calculated for 4 glasses. The results indicate that (1) the equilibrium shifts toward the oxidized state as the Na2O content of the glass increases (plots of log ([Fe2+]/[Fe3+]) vs mol% alkali were linear) and (2) ΔH values for glasses of different composition are nearly equal but differ from the standard (calculated) value for the reaction. The experimental ΔH values were nearly equal to that for the reaction FePO4→1/3 Fe3(PO4)2+ 1/6P2O5+1/4O2, indicating that Fe forms phosphate or polyphosphate configurations in the Na2O-P2O5 glasses. In certain of the glasses studied a faint-pink solid precipitated; its X-ray diffraction pattern indicated that its principal component is crystalline Na2Fe111P3O10.