Structural and Magnetic Study of Undoped and Cu-Doped Rutile TiO2 Single Crystals

Rutile TiO2 single crystals (SCs) were implanted with Cu ions. The implantation effect on microstructure and magnetic behavior of Cu-doped TiO2 wafers was investigated. The implanted ions are in part successfully incorporated in the host lattice gradually forming a CuO-like species. Although the projected range is ∼117 nm, the induced defects extend much deeper. Room temperature ferromagnetism (RTFM) was observed both in undoped and Cu-doped TiO2 SCs. Their saturation magnetizations were found to be nearly equal to each other, in agreement with our theoretical calculations. Additionally, no superparamagnetism was examined in the zero-field cooled (ZFC) versus field cooled (FC) measurements, revealing an intrinsic ferromagnetic nature in each SC.