Calcium Hexaboride Synthesis from Anhydrous Colemanite by Mechanochemical Method

In this study, calcium hexaboride (CaB6) was successfully synthesized from anhydrous colemanite (Ca2B6O11) via a mechanochemical approach. The synthesis process was optimized in two stages: by adjusting the reaction time and varying the carbon-to-colemanite ratio. Structural and compositional analyses were performed using FT-IR, XRD, SEM, and EDX techniques. The optimal synthesis condition was found to be a carbon-to-colemanite ratio of 10:1 and a reaction time of 1020 min, yielding the highest Ca–B vibrational intensities in FT-IR spectra. The mechanochemical method enabled CaB6 formation at ambient conditions without the need for high temperature or pressure, offering a significant advantage over traditional methods. The results suggest that this method can serve as a low-energy route for the synthesis of metal borides, which are promising candidates for applications in refractory materials, electronics, and hydrogen storage systems.