[13a-S203-1~9] 6.3 Oxide electronics

[13a-S203-1] Mott transition of SrVO₃ ultra-thin films grown by gas source MBE

〇KEI S TAKAHASHI¹, Yoshinori Tokura^1,2, Masashi Kawasaki^1,3 (1.RIKEN CEMS, 2.Tokyo College, Univ. of Tokyo, 3.Dept. of Appl. Phys., Univ. of Tokyo)

Keywords:Mott insulator, Molecular beam epitaxy, Vanadium oxide

Two dimantional ultra-thin SrVO₃ films are known to be a Mott insulator while SrVO₃ is a good metal. In this report, we tried to fabricate high quality films of SrVO₃ by gas source molecular beam epitaxy. For the thick (80 nm) film, the resudial resistivity is in the order of 10^-7 Ohmcm, indicating the high crystalline quality. In addition, SrVO₃ ultra-thin films thinner than 4 unit cell show Mott insulating behaviors. Electorn doping into the 2 unit cell SrVO₃ has been attempted by substituting Sr with La. We found that the Mott insulating state changes into a metallic state by 20 % substitution (Sr_0.8La_0.2VO₃).