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

Abstract Nanocrystalline RB 6 (R = Ce and Eu) have been successfully synthesized by a solid-state reaction of CeO 2 and Eu 2 O 3 with NaBH 4 at a temperature range of 900–1200 °C. Phase composition, grain morphology, microstructure and valence states of RB 6 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 CaB 6 -type cubic structure. The present preparation technique is as a novel and invaluable for the developments of highly crystallized RB 6 nanoparticles.