Crystal growth in tellurium flux and characterization of ruthenium dichalcogenides

Growth of RuX2(X = S, Se, Te) by flux method were attempted. Large crystals of RuS2, RuSe0.32Te1.68 and RuTe2 measuring up to 15 × 10 × 10 mm3 with mirror-like surfaces have been grown in tellurium flux by the slow cooling technique with seeds. The stoichiometry of selected crystals are examined by energy dispersive X-ray analysis (EDXA). The difficulties of growing RuSe2 in tellurium flux are reported. Electrical transport properties measurements have revealed n-type semiconducting behavior of the crystals. The optical absorption measurements indicate that the crystals are indirect semiconductors.