Summary: | A novel single-crystal growth method was developed, using arc plasma and metal melt, for a quick survey of high melting point materials. Single crystals of Yb-doped Lu<sub>2</sub>O<sub>3</sub>, Lu<sub>0.388</sub>Hf<sub>0.612</sub>O<sub>1.806</sub>, and Lu<sub>0.18</sub>Hf<sub>0.82</sub>O<sub>1.91</sub>, with melting points of 2460, 2900, and 2840 °C, respectively, were grown by an indirect heating method using arc plasma. We refer to this indirect heating growth method as the core heating (CH) method. The CH-grown Yb1%-doped Lu<sub>2</sub>O<sub>3</sub> sample showed a full width at half maximum of 286 arcsec in the X-ray rocking curve. This value is better than the 393 arcsec obtained for the crystal grown by the micro-pulling-down (μ-PD) method. The Yb charge transfer state (CTS) emission was observed at 350 nm in the Yb1%-doped Lu<sub>2</sub>O<sub>3</sub> and Lu<sub>0.18</sub>Hf<sub>0.82</sub>O<sub>1.91</sub>. In the case of the μ-PD method, using a rhenium (Re) crucible, absorption due to Re contamination and a resulting reduction in the Yb CTS emission were confirmed. However, contamination did not influence the properties observed in the crystals grown by the CH method.
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