It is well known that the incorporation of metal ions in TiO₂ powder may substantially change their bulk and surface properties such as magnetic properties or photocatalytic activity. The main parameters include the character and concentration of the dopant and the thermal treatments.

In this work we present results of the synthesis of transition metal (TM-) doped TiO₂ powders using the Solar Physical Vapor Deposition process (SPVD) in a 2kW solar reactor as well as the characterization using XRD, SEM, TEM and HRTEM, XPS and Raman spectroscopy.

Depending on the air pressure in the solar reactor during the vaporization-condensation process, Anatase or Rutile phase, or a mixture of both, was obtained. Average grain sizes were measured from XRD peaks width. For pure TiO₂ they vary in between 15 and 30 nm.

The Rutile phase is the major phase but the Anatase phase has an important contribution. We have found in Ti_1-xFe_xO₂ targets, that the grain size of the nanopowders depends on the phase studied : the Rutile grain size increases with the metal content increasing (x=0.01 and x=0.02).

Magnetic measurements, performed by SQUID magnetometer, make evident the paramagnetic character of Fe, Co and Mn doped TiO₂ nanopowders.

Acknowledgements

We are indebted to the EC program SOLFACE (6th PCRDT) and to the French ECO-NET program (EGIDE) for supporting a part of this work.