Ab initio Probing of Magnetic and Electronic Properties of Monoclinic ε-WO3 Doped with 3d Transition Metals Within GGA and GGA plus U

Based on ab initio band structure calculations, we have systematically examined the monoclinic tungsten trioxide doped with all 3d metals (M = Sc, Ti, ... , Ni, Cu) focusing on the effects of these impurities on the electronic and magnetic properties of epsilon-WO3. We found that all of the 3d impurity atoms can be divided into two main groups. The first group includes the atoms of the beginning of the 3d row, and for these systems (for example, epsilon-WO3: Ti) the highest magnetic moments and the peculiarities of the near-Fermi states are due to the atoms of the oxygen lattice of trioxides. On the contrary, the impurity atoms of the end of the 3d row play a dominant role in the formation of magnetic and electronic properties. These results are fair for calculations within both GGA and GGA+U approximations. Finally, there are so-called "border" systems (for example, epsilon-WO3:Cr), where the Coulomb interactions have a critical influence on the electronic and magnetic parameters.