TITANIUM DIOXIDE?COBALT MAGNETIC FILM AND METHOD OF ITS MANUFACTURE

摘要

A titanium dioxide cobalt magnetic film is provided that is useful to make up a photocatalyst having high catalytic capability, a semiconductor material having an optical, an electrical and a magnetic function all in combination, and a transparent magnet. The titanium dioxide cobalt magnetic film has a composition expressed by chemical formula: Ti1-xCoxO2 where 0 x /= 0.3, wherein a Ti atom at its lattice position is replaced with a Co atom, and the magnetic film is a film epitaxially grown on a single crystal substrate. The magnetic film has either anatase or rutile crystalline structure, has its band gap energy varying in a range between 3.13 eV and 3.33 eV according to the concentration of Co atoms replaced for Ti atoms at their lattice positions, is capable of retaining its magnetization even at a temperature higher than a room temperature, and is also transparent to a visible light. I the manufacture of the titanium dioxide cobalt magnetic film, a target having TiO2 and Co mixed together at a selected mixing ratio is prepared, placed in a vacuum chamber provided with an atmosphere with a selected oxygen pressure therein, and irradiated in the vacuum chamber with a selected laser light under selected irradiating conditions to cause TiO2 and Co to evaporate from the target and a layer of TiO2 Co to grow in a single crystal substrate that is heated in the vacuum chamber. IMAGE