Response of the lattice across the filling-controlled Mott metal-insulator transition of a rare earth titanate

Abstract

The lattice response of a prototype Mott insulator, SmTiO3, to hole doping is investigated with atomic-scale spatial resolution. SmTiO3 films are doped with Sr on the Sm site with concentrations that span the insulating and metallic sides of the filling-controlled Mott metal-insulator transition (MIT). The GdFeO3-type distortions are investigated using an atomic resolution scanning transmission electron microscopy technique that can resolve small lattice distortions with picometer precision. We show that these distortions are gradually and uniformly reduced as the Sr concentration is increased without any phase separation. Significant distortions persist into the metallic state. The results present a new picture of the physics of this prototype filling-controlled MIT, which is discussed.

Accepted, Phys. Rev. Lett

References in corpus (9)

• Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging
• Orbital Physics in the Perovskite Ti Oxides
• Magnetoelastic coupling in RETiO3 (RE = La, Nd, Sm, Gd, Y)
• Orbital-Spin Structure and Coupling to Lattice in RTiO${}_3$ with R=La,Pr,Nd and Sm
• Coulomb Correlations and the Wigner-Mott Transition
• First-order melting of a weak spin-orbit Mott insulator into a correlated metal
• Direct observation of charge mediated lattice distortions in complex oxide solid solutions
• Phase separation in doped Mott insulators
• The Anderson-Mott transition induced by hole-doping in Nd1-xTiO3