Chemical synthesis and microstructure of nanocrystalline RB6 (RÂ =Â Ce, Eu)

Nanocrystalline RB6 (R = Ce and Eu) have been successfully synthesized by a solid-state reaction of CeO2 and Eu2O3 with NaBH4 at a temperature range of 900-1200 °C. Phase composition, grain morphology, microstructure and valence states of RB6 were investigated by using XRD, FESEM, HRTEM and XANES measurements. Results show that all the synthesized hexaborides are composed of single-phase nanoparticles with cubic morphology. The FFT patterns of HRTEM images reveal that the hexaborides have a high crystallinity with CaB6-type cubic structure. The present preparation technique is as a novel and invaluable for the developments of highly crystallized RB6 nanoparticles.