Synthesis of one-dimensional rare earth hexaborides nanostructures and their optical absorption properties

We developed a general solid state reaction to synthesize both single and dual rare earth hexaborides (REB6) under autogenic pressure. Through a series of nearly similar experiments, one-dimensional (1-D) single crystalline REB6 (RE=La, Ce, Pr, Nd and Sm) nanostructures can be formed. Detailed structures, morphology and chemical composition of the synthesized samples were studied by XRD, SEM, TEM, EDS and elemental mapping techniques. As a rarely reported solid state reaction for especially 1-D nanostructures growth, the formation mechanism was explored and discussed here. Gaseous species containing boron and rare earth under high pressure was deemed to be important. Optical absorption tests were carried out for all the synthesized samples at the first time. Results indicate a tunable VL transmittance can be achieved in LaxSm1-xB6 nanostructures upon x variation.