Electrolytic preparation of CaB6 by molten salt technique

Calcium hexaboride (CaB6) crystals with high melting point (2,235 A degrees C) have been conveniently synthesized at low temperature (900 A degrees C) from molten salt electrolysis. The synthesis was carried out using CaO-B2O3-LiF melt under argon atmosphere. Electrochemical experiments were carried out in an inconel reactor to having a high purity graphite crucible, which served as an electrolyte holding vessel as well as the anode. An electropolished molybdenum rod was employed as the cathode. The electrolysis was performed at 900 A degrees C under argon atmosphere at current densities ranging from 0.5 to 1.5 A/cm(2) at 1:6 M ratios of calcium and boron content. After the electrolysis, the cathode product was removed and cleaned using dilute HCl solution followed by triple distilled water. Characterization of the crystalline product by TG/DTA, XRD, CHNS, EDAX, XPS, EPR, and SEM were reported. From the studies, it has been observed that CaB6 can be synthesized at all current densities and the products have some impurities.