Superconductivity of Mg/MgO interface formed by shock-wave pressure

A mixture of Mg and MgO has been subjected to a shock-wave pressure of ≈170 kbar. The ac susceptibility measurements of the product has revealed a metastable superconductivity with Tc ≈ 30 K, characterized by glassy dynamics of the shielding currents below Tc. Comparison of the ac susceptibility and the dc magnetization measurements infers that the superconductivity arises within the interfacial layer formed between metallic Mg and its oxide due to the shock-wave treatment.

► Mg/MgO interface superconducting at ∼30 K was formed by shock-pressure technique.
► Dynamic magnetic susceptibility of the interface was studied.
► Glassy dynamics of the superconducting shielding currents was observed.
► The superconducting interface is instable under normal conditions.