Magnetism and structure of Cu2O1+x and 3d-doped TiO2-x nanopowders

The structural features and magnetic properties of non-stoichiometric nanocrystalline semiconductors Cu2O1+x and TiO2-x doped with 3d-metals were investigated. The nanopowders were obtained by gas-phase synthesis in the oxygen contained argon atmosphere. For nanocrystalline samples Cu2O1+x with oxygen concentration more than stoichiometry (x>0) magnetic hysteresis properties up to temperatures above room temperature (RT) were discovered. In the case of oxygen deficit in TiO2-x on the condition that rutile or anatase structure remains, the magnetic moment value grows and the magnetization curves at RT become nonlinear. On doping TiO2-x with cobalt, the magnetic moment value increases without indications of magnetic ordering at RT. In the optical absorption spectra of Cu2O1+x nanopowders at 77K, the peaks in the range of wavelengths 480 and 460nm were revealed, which are close to peaks at n=1 of the blue and indigo exciton series for Cu2O single crystal