It is one of the fundamental compounds formed in reactions between erbium and boron. The compound is isostructural with all other reported rare-earth hexaboride compounds including lanthanum hexaboride, samarium hexaboride, and cerium hexaboride.[1] Due to the isostructural nature of the rare-earth hexaborides and the strong interaction of boron octahedra within the crystal, these compounds show a high degree of lattice matching which suggests the possibility of doping by substituting one rare earth metal within the crystal with another.[2][3] Until recently, it had been hypothesized that erbium hexaboride was unstable due to the small size of the Er3+ cation within the crystal structure when compared to the ionic radii of other rare-earth elements that form known rare-earth hexaboride compounds.[4] It has now been demonstrated, however, that new nanoscale synthetic methods are capable of producing high-purity, stable erbium hexaboride nanowires. These wires, produced using chemical vapor deposition (CVD), have a reported lattice constant of 4.1 Å.[5]
References
^Samsonov, Grigorii (1965). High-Temperature Compounds of Rare Earth Metals with Nonmetals. New York: Consultants Bureau.
^Mar, R. W. (1973). "Conditions for Formation of ErB6". Journal of the American Ceramic Society. 56 (5): 275–278. doi:10.1111/j.1151-2916.1973.tb12487.x.
^Gernhart, Zane; R. M. Jacobberger; L. Wang; J. R. Brewer; M. A. Dar; D. R. Diercks; W. N. Mei; C. L. Cheung (December 2012). "Existence of Erbium Hexaboride Nanowires". Journal of the American Ceramic Society. 95 (12): 3992–3996. doi:10.1111/j.1551-2916.2012.05427.x.