A magnetic substructure for use in a magnetic device, the magnetic substructure (100; 100'; 100"; 100"') comprising: a plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102"); a plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") being interleaved with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n') inducing a perpendicular anisotropy in the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102"), wherein the magnetic substructure (100; 100'; 100"; 100"') is configured to be switchable between a plurality of stable magnetic states when a write current is passed through the magnetic substructure (100; 100'; 100"; 100"') and wherein the perpendicular anisotropy corresponds to a perpendicular anisotropy energy, characterized in that the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") are immiscible with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n') and chemically stable with respect to the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") are substantially free of a magnetically dead layer-producing interaction with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), and the magnetic substructure (100; 100'; 100"; 100"') has an out-of-plane demagnetization energy, the perpendicular anisotropy energy being greater than the out-of-plane demagnetization energy. a plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102"); a plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") being interleaved with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n') inducing a perpendicular anisotropy in the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102"), wherein the magnetic substructure (100; 100'; 100"; 100"') is configured to be switchable between a plurality of stable magnetic states when a write current is passed through the magnetic substructure (100; 100'; 100"; 100"') and wherein the perpendicular anisotropy corresponds to a perpendicular anisotropy energy, characterized in that the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") are immiscible with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n') and chemically stable with respect to the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), the plurality of ferromagnetic layers (102; 102'; 102-1, 102-2, 102-3; 102") are substantially free of a magnetically dead layer-producing interaction with the plurality of nonmagnetic layers (104; 104'; 104-1, 104-2, 104-n; 104-1', 104-2', 104-n'), and the magnetic substructure (100; 100'; 100"; 100"') has an out-of-plane demagnetization energy, the perpendicular anisotropy energy being greater than the out-of-plane demagnetization energy.