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

Abstract The structural features and magnetic properties of non-stoichiometric nanocrystalline semiconductors Cu 2 O 1+ x and TiO 2− x doped with 3d-metals were investigated. The nanopowders were obtained by gas-phase synthesis in the oxygen contained argon atmosphere. For nanocrystalline samples Cu 2 O 1+ 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 TiO 2− 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 TiO 2− x with cobalt, the magnetic moment value increases without indications of magnetic ordering at RT. In the optical absorption spectra of Cu 2 O 1+ x nanopowders at 77 K, the peaks in the range of wavelengths 480 and 460 nm were revealed, which are close to peaks at n =1 of the blue and indigo exciton series for Cu 2 O single crystal.