Magnetic resonance (FMR, EPR) of chromium dioxide supported on titania

Ferromagnetic resonance (FMR) investigations (ν=9.5 and 35 GHz) of chromium dioxide, CrIVO2, supported on titania for different chromium contents (0.7, 7 and 11 wt% Cr) are reported. CrO2 particle diameters of 3–4 nm were calculated from the thermomagnetic curves (Griscom's model). The temperature dependence of the line widths and simulations of the FMR powder spectra indicate contributions of axial anisotropy and additionally strong interactions of CrO2 with the TiO2 surface. In addition to Cr(IV), varying amounts of Cr(V) and Cr(VI) were observed