Abstract Scope |
We present the structural behavior of two metal hexaboride solid solutions, Ca<sub><i>x</i>-1</sub>M<sub><i>x</i></sub>B<sub>6</sub> and Sr<sub><i>x</i>-1</sub>M<sub><i>x</i></sub>B<sub>6</sub> (<i>x</i> = 0, 0.1, 0.3, 0.5), where M can be Li, Na, or K; and show their evolution as the experimental concentration, <i>x</i>, is increased. The powders were synthesized by combustion synthesis, acid-washed with an HCl solution, and characterized using X-ray diffraction (XRD), electron energy-loss spectroscopy (EELS), electron diffraction, and transmission and scanning electron microscopy. Electron micrographs mostly show cubic morphologies with a particle size range from ~100 nm to 1 µm, while XRD diffractograms show the formation of some amorphous character together with the crystalline phase as <i>x</i> increases. Electron diffraction show that the structures possess a high degree of crystallinity, with minimal misalignments and changes in crystallite orientation. EELS analyses suggest a homogeneous distribution of the dopant ions across the cubic nanoparticles. |