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SmB₆₂ single crystals were successfully grown by the floating zone (FZ) method. The high-temperature thermoelectric properties were investigated, together with magnetic properties and specific heat at low-temperature. The electrical resistivity, ρ, shows variable-range-hopping (VRH) behavior with significantly lower values than other rare-earth RB₆₂ (RB₆₆) compounds. An effective magnetic moment, μ_eff, of 0.42 μ_B/Sm was estimated, which if straightforwardly taken indicates a mixed valency for SmB₆₂ with Sm²⁺:Sm³⁺ = 1:1, which is the first ever indicated for RB₆₆-type compounds. Localization length of the VRH at the Fermi level, ξ, was estimated to be 3.33 Å indicating that carriers in SmB₆₂ are much less localized than in YB₆₆ which has 0.56 Å. The thermoelectric behavior of SmB₆₂ is striking, with ρ reduced by two orders of magnitude while maintaining large Seebeck coefficients, and as a result the …