We determined the activation volumes (V*) for polycrystalline magnesite with grain sizes of 2 and 80 µm deforming by low temperature plasticity (LTP) mechanisms (kinking and dislocation glide). diffusion creep. and dislocation creep at temperatures of 500. 750. https://parisnaturalfoodes.shop/product-category/magnesium-synergy-powder/