MTJ material stacks including one or more material layers that have outdiffused one or more dopants through a layer sidewall edge, MTJ devices employing such stacks, and computing platforms employing such MTJ devices. A free magnet layer or fixed magnet layer may include a dopant, such as boron. A liner layer may be deposited over an MTJ stack, for example in close proximity to the edge of at least one of the fixed or free magnet layers. During a thermal anneal, a dopant, such as boron, may be gettered by the liner. Dopant gettering by the liner may facilitate changes with in the MTJ stack, such as development of perpendicular magnetic anisotropy within a magnet layer. Following dopant gettering, the liner may be retained, or at least partially removed as sacrificial.