It has been suggested that Ba₃In₂O₆ might be a high-T_c superconductor. Experimental investigation of the properties of Ba₃In₂O₆ was long inhibited by its instability in air. Recently epitaxial Ba₃In₂O₆ with a protective capping layer was demonstrated, which finally allows its electronic characterization. The optical bandgap of Ba₃In₂O₆ is determined to be 2.99 eV in-the (001) plane and 2.83 eV along the c-axis direction by spectroscopic ellipsometry. First-principles calculations were carried out, yielding a result in good agreement with the experimental value. Various dopants were explored to induce (super-)conductivity in this otherwise insulating material. Neither A- nor B-site doping proved successful. The underlying reason is predominately the formation of oxygen interstitials as revealed by scanning transmission electron microscopy and first-principles calculations. Additional efforts to induce superconductivity were investigated, including surface alkali doping, optical pumping, and hydrogen reduction. To probe liquid-ion gating, Ba₃In₂O₆ was successfully grown epitaxially on an epitaxial SrRuO₃ bottom electrode. So far none of these efforts induced superconductivity in Ba₃In₂O_6, leaving the answer to the initial question of whether Ba₃In₂O₆ is a high-T_c superconductor to be 'no' thus far.

العنوان

Journal of Physics: Condensed Matter

الناشر

IOP Publishing

بلد الناشر

الولايات المتحدة الأمريكية

Indexing

Thomson Reuters

معامل التأثير

2,3

نوع المنشور

Both (Printed and Online)

المجلد

36

السنة

2024

الصفحات

315602