Structure and properties of hydrogen-intercalated YBa2Cu3Oy

The effect of hydrogenation at 150 and 200°С on the structure and magnetic susceptibility of YBa₂Cu₃O_y (123) with different hydrogen contents has been studied. Upon the incorporation of hydrogen, the phase transition of the 123 phase into a defect tetragonal 124 phase occurs. In contrast to the transition upon hydration, the phase transition upon hydrogenation takes place only for compounds characterized by high oxygen contents (y > 6.5). Depending on the compound structure and oxygen content, hydrogen atoms can both occupy interstitials in Cu–O planes to form HYBa₂Cu₃O₆ and join with oxygen to form an oxide–hydroxide. In contrast to hydration, upon hydrogenation of YBa₂Cu₃O_y, the substitution of europium for yttrium and alloying with cerium and zirconium oxides do not block the intercalation of hydrogen into the structure of the 123 compound.