A magnetic cell includes magnetic, secondary oxide, and getter seed regions. During formation, a diffusive species is transferred from a precursor magnetic material to the getter seed region, due to a chemical affinity elicited by a getter species. The depletion of the magnetic material enables crystallization of the depleted magnetic material through crystal structure propagation from a neighboring crystalline material, without interference from the now-enriched getter seed region. This promotes high tunnel magnetoresistance and high magnetic anisotropy strength. Also during formation, another diffusive species is transferred from a precursor oxide material to the getter seed region, due to a chemical affinity elicited by another getter species. The depletion of the oxide material enables lower electrical resistance and low damping in the cell structure. Methods of fabrication and semiconductor devices are also disclosed.