New phases in the SrO–La2O3 –TiO2–CuO system with the K2NiF4 structure

Structure and Magnetic Properties of Oxygen Pressure Induced Sr1.5La0.5Cu0.5Ti0.5O4-δ (0.0 ≤ δ ≤ 0.25)

“…Cu III , in an oxygen lattice, can be induced by high oxygen pressure treatment , or particular electrochemical oxidation at low temperature and chemical oxidation in sodium hypobromite solution . The chemical oxidation procedure has been applied to induce superconductivity by oxygen intercalation into the system La 2 - x Sr x Cu 1 - x /2 Ti x /2 O 4 - δ , which corresponds to a solid solution between La 2 CuO 4 and Sr 2 TiO 4 . However, this solid solution could not avoid the oxygen vacancy and complete oxidation of copper was not achieved by the chemical oxidation.…”

“…4 The chemical oxidation procedure has been applied to induce superconductivity by oxygen intercalation into the system La 2-x Sr x Cu 1-x/2 Ti x/2 O 4-δ , which corresponds to a solid solution between La 2 CuO 4 and Sr 2 TiO 4 . 5 However, this solid solution could not avoid the oxygen vacancy and complete oxidation of copper was not achieved by the chemical oxidation.…”

Mossbauer Spectroscopic Study of La2-2xSr2xCu1-xFexO4-y(0≤x≤0.5) Solid-solution

“…The alkaline-earth metal substitution at the lanthanum site is particularly important for the superconducting behavior of this oxide. [1][2][3][4] More generally, the physical properties of A 2 BO 4 oxides are largely dependent on the formal valence of transition metal ions (B) and/or the lattice volumes. 5,6 Partial substitution at the A-and B-sites or variation of oxygen vacancy can vary the valence of B ions in A 2 BO 4 , which often gives rise to the change in the lattice constants because of the interaction between the transition metal ions and oxygen ions.…”