Electron magnetic resonance investigation of chromium diffusion in yttria powders

Abstract

The electron magnetic resonance (EMR) technique was used to investigate the diffusion of chromium in yttria (Y₂O₃) powders. The EMR absorption intensity was measured for several annealing times and three different temperatures of isothermal annealing: 1273, 1323 and 1373 K. The activation temperature for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be E_A=342±5 kJ mol⁻¹. This value is larger than the activation energy for the diffusion of chromium in rutile (TiO₂), periclase (MgO) and cobalt monoxide (CoO) and smaller than the activation energy for the diffusion of chromium in chrysoberyl (BeAl₂O₄).