Investigation of the LiNO$_3$–KNO$_3$–LiClO$_4$ salt system

The LiNO$_3$–KNO$_3$ nitrate eutectic was investigated at different additions of lithium perchlorate by methods of differential scanning calorimetry, X-ray phase analysis and Raman spectroscopy, and data on electrical conductivity were obtained. It was found that the addition of lithium perchlorate to the nitrate eutectic leads to an increase in the specific ionic conductivity of the ternary salt system. It was found that with the increase of LiClO$_4$ addition the melting peak of LiNO$_3$–KNO$_3$ eutectic decreases and for the composition with the initial content of 0.5LiClO$_4$ the phase transition of LiNO$_3$–KNO$_3$ eutectic is not registered, which is associated with the exchange reaction between potassium nitrate and lithium perchlorate with the formation of KClO$_4$ and LiNO$_3$. This conclusion is confirmed by X-ray diffraction analysis of the system and Raman spectra, from which it follows that with increasing LiClO$_4$ addition the peak of full-symmetric valence vibration $\nu_1$ (KNO$_3$) decreases and the peak $\nu_1$ (KClO$_4$) is observed. When 0.5 mole fraction of LiClO$_4$ is added, the $\nu_1$ (KNO$_3$) peak completely disappears.