相关论文: Percolative Ferromagnetism in Anatase Co:TiO2

Here we present a study of magnetism in \CTO\ anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transition electron microscopy analyses…

Oxide based diluted magnetic semiconductor (DMS) materials have been a subject of increasing interest due to reports of room temperature ferromagnetism in several systems and their potential use in the development of spintronic devices.…

Colloidal cobalt-doped TiO2 (anatase) nanocrystals were synthesized and studied by electronic absorption, magnetic circular dichroism, transmission electron microscopy, magnetic susceptibility, cobalt K-shell X-ray absorption spectroscopy,…

Pulsed laser deposited films of Co doped anatase TiO2 are examined for Co substitutionality, ferromagnetism, transport, magnetotransport and optical properties. Our results show limited solubility (up to ~ 2 %) of Co in the as-grown films…

Ferromagnetism is observed at and above room temperature in pulsed laser deposited epitaxial films of Co-doped Ti-based oxide perovskite (La1-xSrxTiO3-d). The system has the characteristics of an intrinsic diluted magnetic semiconductor…

We have studied magnetism in anatase Ti$_{1-x}$Co$_x$O$_{2-\delta}$ ({\it x} = 0.05) thin films with various electron carrier densities, by soft x-ray magnetic circular dichroism (XMCD) measurements at the Co $L_{2,3}$ absorption edges. For…

Magneto-optical spectroscopy of a transparent ferromagnetic semiconductor, anatase TiO2 doped with Co, is carried out at room temperature. A large magneto-optical response with ferromagnetic field dependence is observed throughout from…

The existence of high-temperature ferromagnetism in thin films and nanoparticles of oxides containing small quantities of magnetic dopants remains controversial. Some regard these materials as dilute magnetic semiconductors, while others…

Electric and magnetic properties of a high temperature ferromagnetic oxide semiconductor, cobalt-doped rutile TiO2, are summarized. The cobalt-doped rutile TiO2 epitaxial thin films with different electron densities and cobalt contents were…

It is shown that dilute niobium doping has significant effect on the ferromagnetism and microstructure of dilutely cobalt-doped anatase TiO2 films. Epitaxial films of anatase TiO2 with 3% Co, without and with 1% niobium doping were grown by…

We study the surface and bulk electronic structure of the room-temperature ferromagnet Co:TiO2 anatase films using soft and hard x-ray photoemission spectroscopy with probe sensitivities of ~1 nm and ~10 nm, respectively. We obtain direct…

Anatase Ti0.96Co0.04O2 films were grown epitaxially on SrTiO3 (001) substrates by using plused laser deposition with in-situ reflection high-energy electron diffraction. The oxygen partial pressure, PO2, during the growth was systematically…

We report a first-principles study on the geometric, electronic and magnetic properties of V-doped anatase TiO$_{2}$. The DFT+U (Hubbard coefficient) approach predicts semiconductor band structures for Ti$_{1-x}$V$_{x}$O$_{2}$ (x=6.25 and…

Recently theoretical works predict that some semiconductors (e.g. ZnO) doped with magnetic ions are diluted magnetic semiconductors (DMS). In DMS magnetic ions substitute cation sites of the host semiconductor and are coupled by free…

We synthesized pure and Co-doped (6.25 12.5 at.) ZrO$_2$ nanopowders in order to study their magnetic properties.We analyzed magnetic behavior as a function of the amount of Co and the oxygenation, which was controlled by low pressure…

Pure rutile Co-doped TiO$_2$ films were fabricated successfully by the conventional pulsed laser deposition technique on silicon substrates from a ceramic target. Under the right fabrication conditions, Co concentration in the films could…

TiO$_{2-\delta}$ films were deposited on (100) Lanthanum aluminates LaAlO$_{3}$ substrates at a very low oxygen chamber pressure $P\approx 0.3$ mtorr employing a pulsed laser ablation deposition technique. In previous work, it was…

The existence of semiconductors exhibiting long-range ferromagnetic ordering at room temperature still is controversial. One particularly important issue is the presence of secondary magnetic phases such as clusters, segregations, etc...…

The authors investigated the structure and properties of GdBaCo$_{2}$O$_{5.5+\delta}$ thin films epitaxially grown on SrTiO$_{3}$ (001) single crystal substrates. The thin films were found to have a notable remnant magnetization above room…

Soft x-ray magnetic circular dichroism (XMCD) measurements at the Co L2,3 edges of Co doped rutile TiO2 at room temperature have revealed clear multiplet features characteristic of ferromagnetic Co2+ ions coordinated by O2- ions, being in…