Grain Boundary Diffusion of Magnesium in Zirconia

This paper reports the transport kinetics of Mg in cubic yttria‐stabilized zirconia (containing 10% mol of Y 2 O 3 (10YSZ)) involving the bulk and the grain boundary diffusion coefficients. The diffusion‐controlled concentration profiles of Mg were determined using secondary ion mass spectrometry (SIMS) in the range 1073–1273 K. The determined bulk diffusion coefficient and the grain boundary diffusion product may be expressed as the following functions of temperature, respectively: D = 5.7 exp[(−390 kJ/mol)/ RT ] cm 2 ·s −1 and D ′αδ= 3.2 × 10 −15 exp[(−121 kJ/mol)/ RT ] cm 3 ·s −1 , where α is the segregation enrichment factor and δ is the boundary layer thickness. The grain boundary enhancement factor decreases with temperature from 10 5 at 1073 K to 10 3 at 1273 K.