Anisotropy of the erbium dodecaboride thermionic properties

There were studied temperature dependences of the ErB12 (100), (110) and (111) electron work functions in the temperature range T = (1200 ÷ 1800) K at pressure p < 10−4 Pa and found their anisotropy. Graphical modeling of the ErB12 (100), (110) and (111) crystallographic planes was performed. The calculated reticular densities for two ion types (B, Er) in these planes have showed that decreasing of electron work function of the ErB12 planes in row (100) → (110) → (111) correlates with the decreasing of the surface B/Er ratio in the same row.

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► The thermionic current density measurements of ErB12 (100), (110) and (111).
► The electron work functions anisotropy of ErB12 single crystals.
►  Ions reticular density calculations.
► The lower electron work function correlates with the lower B/Er ratio in the plane.