The stabilization of phase III and phase I in sodium sulfate by aliovalent cation substitution
The stabilization of phase III and phase I in sodium sulfate by aliovalent cation substitution
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DOI：
10.1063/1.465562
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发表时间：
1993-12
影响因子：
4.4
通讯作者：
G. Dharmasena;R. Frech
中科院分区：
文献类型：
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作者：
G. Dharmasena;R. Frech
相I和相III在Na2SO4中通过用异价阳离子Y 3+、La 3+、Dy 3+、Ce 4+和Ca 2+的硫酸盐取代而在室温下稳定。利用激光拉曼光谱测量硫酸根阴离子的内光模，研究了硫酸根阴离子的相稳定。相III通过十分之几摩尔百分比的取代基稳定，而相I通过大约十倍于该浓度稳定。相I和相III的稳定似乎并不显著依赖于客体离子的电荷。的焓和熵的相III相I过渡被发现显着降低取代基阳离子浓度的增加。
Both phase I and III in Na2SO4 have been stabilized at room temperature by substitution with the sulfate salts of the aliovalent cations Y3+, La3+, Dy3+, Ce4+, and Ca2+. Phase stabilization has been studied using laser Raman spectroscopy to measure the internal optic modes of the sulfate anion. Phase III is stabilized by a few tenths of a mole percent of the substituent, while phase I is stabilized by roughly ten times that concentration. Stabilization of both phase I and phase III does not appear to depend significantly on the charge of the guest ion. The enthalpy and entropy of the phase III to phase I transition was found to decrease markedly with increasing substituent cation concentration.