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

Changes of Subsurface Properties due to Fatigue Determined by Sin2ψ-method and Harmonic Analysis of Eddy Current Signals

Monitoring residual stress relaxation due to mechanical loading has the capability to retrieve a component's load history. So far, these changes are determined by X-ray diffraction using the sin2ψ-method going along with high effort regarding specimen preparation, measurement time and costs. The presented paper evaluates harmonic analysis of eddy current measurements as an alternative technology to determine alterations of a component's subsurface due to fatigue. Transferring this approach to a wide range of machined components and mass production bears the potential to gain access to large databases of service life information, representing an important enabling technology for cyber-physical systems