The rich phenomena in the FeSe and related compounds have attracted great interests as it provides fertile material to gain further insight into the mechanism of high temperature superconductivity. A natural follow-up work was to look into the possibility of superconductivity in MnSe. We demonstrated in this work that high pressure can effectively suppress the complex magnetic characters of MnSe, and induce superconductivity with Tc ~ 5 K at pressure ~12 GPa confirmed by both magnetic and resistive measurements. The highest Tc is ~ 9 K (magnetic result) at ~35 GPa. Our observations suggest the observed superconductivity may closely relate to the pressure-induced structural change. However, the interface between the metallic and insulating boundaries may also play an important role to the pressure induced superconductivity in MnSe.

Carbon@titania yolk–shell nanostructures are successfully synthesized at different calcination conditions. These unique structure nanomaterials can be used as a photocatalyst to degrade the emerging water pollutant, acetaminophen (paracetamol). The photodegradation analysis studies have shown that the samples with residual carbon nanospheres have improved the photocatalytic efficiency. The local electronic and atomic structure of the nanostructures are analyzed by X‐ray absorption spectroscopy (XAS) measurements. The spectra confirm that the hollow shell has an anatase phase structure, slight lattice distortion, and variation in Ti 3d orbital orientation. In situ XAS measurements reveal that the existence of amorphous carbon nanospheres inside the nano spherical shell inhibit the recombination of electron–hole pairs; more mobile holes are formed in the p–d hybridized bands near the Fermi surface and enables the acceleration of the carries that significantly enhance the photodegradation of paracetamol under UV–visible irradiation. The observed charge transfer process from TiO2 hybridized orbital to the carbon nanospheres reduces the recombination rate of electrons and holes, thus increasing the photocatalytic efficiency.

Transition metal oxides films exhibit strong structure-property correlations which foster innovative physical properties that are not present in their bulk counterparts. This study has successfully prepared different thickness-dependent epitaxial Ti2O3 thin films on MgO (001) single crystal substrate using the pulsed laser deposition (PLD) method. The results reveal a strong correlation between the crystal structure and superconductivity in Ti2O3 thin films. Synchrotron X-ray diffraction (XRD) and high resolution transmission electron microscope measurements confirmed that the appearance of superconductivity is closely related to the coexistence of the cubic-Ti2O3 (γ-Ti2O3 ) and orthorhombic-Ti2O3 (o-Ti2O3) phases. Superconductivity is absent in 80 nm film, which exhibits only a single γ-Ti2O3 phase. The highest superconducting transition temperature (TC) ~ 7.2 K is achieved in 1200 nm film, which shows about 55% o-Ti2O3 phase and 45% γ-Ti2O3 phase. Room temperature Raman data suggest that Eg modes at ~ 330 cm-1 and ~430 cm-1 may associate with superconductivity, and an Eg mode at ~660 cm-1 is related to the insulating behavior observed in 80 nm film.