Diffusion of transition metals in periclase by experiment and first-principles, with implications for core-mantle equilibration during metal percolation

Diffusion of the divalent transition metals in the deep mantle is important for understanding length scales of mantle heterogeneity, transport across the core–mantle boundary, and the degree of equilibration during core formation. Here we report the results of experiments and theoretical calculations on Ni, Co, Fe and Mn diffusion in periclase, the primary repository of these elements in Earth’s lower mantle. The periclase used in the experiments was doped with 550 ppm Al 3 þ to fix the cation vacancy concentration, and the experiments were performed at 2 GPa and temperatures between 1673 and 2073 K. The variation in diffusion coefficients among the transition metals was ��