Role of Ti 3d carriers in mediating the ferromagnetism of CoTiO2 anatase thin films

T. Ohtsuki, A. Chainani, R. Eguchi, M. Matsunami, Y. Takata, M. Taguchi, Y. Nishino, K. Tamasaku, M. Yabashi, T. Ishikawa, M. Oura, Y. Senba, H. Ohashi, S. Shin

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


We study the surface and bulk electronic structure of the room-temperature ferromagnet CoTiO2 anatase films using soft- and hard-x-ray photoemission spectroscopy with probe sensitivities of ∼1 and ∼10nm, respectively. We obtain direct evidence of metallic Ti3+ states in the bulk, which get suppressed to give a surface semiconductor, thus indicating the difference in electronic structure between surface and bulk. X-ray absorption and resonant photoemission spectroscopy reveal Ti3+ electrons at the Fermi level (EF) and high-spin Co2+ electrons occurring away from EF. The results show the importance of the charge neutrality condition: Co2++VO2-+2Ti4+ Co2++2Ti3+ (VO is oxygen vacancy), which gives rise to the elusive Ti 3d carriers mediating ferromagnetism via the Co 3d-O 2p-Ti 3d exchange interaction pathway of the occupied orbitals.

Original languageEnglish
Article number047602
JournalPhysical review letters
Issue number4
Publication statusPublished - 2011 Jan 25

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


Dive into the research topics of 'Role of Ti 3d carriers in mediating the ferromagnetism of CoTiO2 anatase thin films'. Together they form a unique fingerprint.

Cite this