(東北大學(xué) 冶金學(xué)院，沈陽(yáng) 110819)
摘 要: 利用Raman光譜法研究不同溫度下的KF-KBF4熔鹽的離子結(jié)構(gòu)。結(jié)果表明：KF摩爾分?jǐn)?shù)為0.1~0.7的熔鹽體系中，存在BF63-和BF4-兩種絡(luò)合離子團(tuán)，其中BF63-的v1振動(dòng)峰的Raman位移在710 cm-1附近。隨著溫度的增加，各振動(dòng)基團(tuán)結(jié)構(gòu)松散，原子間的作用力變?nèi)酰駝?dòng)無(wú)序性增加。隨著混合物中KF含量的增加，由于K+對(duì)絡(luò)合離子團(tuán)中F-的吸引力和B3+的排斥力的增加，絡(luò)合離子團(tuán)的結(jié)構(gòu)更加松散，同時(shí)BF63-的相對(duì)含量增加。獲得了BF63-和BF4-的v1振動(dòng)對(duì)應(yīng)的特征峰的強(qiáng)度比與溫度的定量關(guān)系，可以以此為依據(jù)進(jìn)行熔鹽體系中絡(luò)合離子團(tuán)濃度的計(jì)算。
關(guān)鍵字: Raman光譜學(xué)；BF63-；KF-KBF4熔鹽；離子結(jié)構(gòu)；絡(luò)合離子團(tuán)
（School of Metallurgy, Northeastern University, Shenyang 110819, China）
Abstract:The ionic structure of molten KF-KBF4 at different temperatures was studied by Raman spectroscopy. The results show that two kinds of complex, BF63- and BF4-, are co-existed in the melts in which the molar fraction of KF is from 0.1 to 0.7, and v1 characteristic peak of BF63- is located at about 710 cm-1. Higher temperature leads to looser structure of the complexes, weaker interatomic force and more disorder vibration. With the increase of the molar fraction of KF in the mixture, the complexes become looser due to the increase of attraction force between K+ and F- and repulsion force between K+ and B3+ in the complexes. Meanwhile, the relative content of BF63- increases. The intensity ratio of v1 characteristic peak corresponding to BF63- to BF4- is obtained, which lays a foundation for calculation of concentration of the complex in the melts.
Key words: Raman spectroscopy; BF63-; KF-KBF4 molten salts; ionic structure; complex
