Valence instability and photochemical reaction at surface of strongly correlated MgTi2O4

Abstract

We have studied surface electronic structure and light illumination effect of spinel-type MgTi2O4 with Ti3+(d1) electronic configuration. Ti4+ species are found at surfaces of MgTi2O4, which show photo-induced effect similar to the Ti4+-oxide semiconductors with surface depletion layer. MgTi 2O4 with the surface Ti4+ states reacts with water for H2 emission, which is largely enhanced by light illumination. © 2013 Author(s).