“…Flux synthesis has been utilized widely for the synthesis of solid-state materials (Oishi et al, 2004;Akira et al, 2019), especially for discovering compounds with complex structures (DiSalvo and Clarke, 1996; Bugaris and zur Loye, 2012) Nonetheless, an interesting feature of synthesis using a flux, in addition to structural determination, is to explore various properties (Yamane et al, 1997;Mizuno et al, 2014;Miura et al, 2016;Chiang et al, 2018). Superconducting materials also can be synthesized by the flux method, and the properties of the synthesized products can be controlled by the synthesis condition (Nagao, 2017). For example, we very recently found that Sm(O,F)BiS 2 single crystals synthesized by KCl-KI exhibited superconductivity (Kinami et al, 2019), in contrast to the non-superconducting Sm(O,F)BiS 2 powder and crystals synthesized using CsCl-KCl flux reported previously (Thakur et al, 2015).…”