Phase control and growth of Y123 and Y124 crystals below 600°C by molten KOH flux

Low-temperature liquid-phase epitaxy of YBa2Cu3Oy films by the molten KOH method

“…Recently, we have reported that the p-T phase diagram of Y123 and Y124 with KOH depended on the growth atmosphere. 26,27) To establish a low-temperature fabrication method of Y123 films, we fabricated Y123 films on an NGO (001) substrate by the molten KOH method in reducing atmosphere and discussed their orientation, growth mode, and superconducting properties.…”

Fabrication of a superconducting YBa2Cu4O8 film via coprecipitation

“…On the other hand, REBa 2 Cu 4 O 8 (RE-124) has a rigorous thermal stability for oxygen contents at high temperatures up to 800 °C. [15][16][17][18][19] In particular, Y-124 exhibits a higher superconducting transition temperature T c (∼80 K [15][16][17][18][19] ) than the liquid nitrogen temperature and its T c can be increased up to 90 K by the partial Ca substitution of the Y site. 20,21) Hence Y-124 is an important material for superconducting application above liquid nitrogen temperature.…”

“…However, it is not easy to synthesize the Y-124 phase under ambient conditions according to the pressure-temperature phase diagram of the Y-Ba-Cu-O system. [15][16][17][18][19] In order to apply Y-124 to superconducting technologies, it is necessary to overcome the problem and develop a simple fabrication method for Y-124 films.…”

“…The purpose of this study is to fabricate the Y-124 film for applications such as a Y-123 tape. 12) We referred to the phase diagram of the Y-Ba-Cu-O system reported by Yamada et al using the potassium hydroxide (KOH) flux method 19) and used the coprecipitation process in the Y-124 phase as reported by Ho et al 22) Compared to the previous studies on the oriented Yb-124 films by the coating-pyrolysis method 23) and the c-axis oriented but multiphasic Y-124 (+Y-123) films by a pulsed laser deposition method, 24) we have successfully fabricated the c-axis oriented Y-124 film easily without dangerous sources and complex configurations, which does not contain the Y-123 phase.…”

“…Starting materials of Y(NO 19) X-ray diffraction (XRD) pattern was measured by the θ-2θ method with a CuKα radiation using Mini Flex 600 (Rigaku). The sample morphology and the chemical composition were identified by a scanning electron microscope (SEM) using JSM6010-LA (JEOL) equipped with an energy dispersive Xray analyzer (EDX).…”