Spin-gapless and half-metallic ferromagnetism in potassium and calcium δ -doped GaN digital magnetic heterostructures for possible spintronic applications: insights from first principles

The reports previously issued predominantly paid attention to the d -block magnetic elements δ -doped digital magnetic materials. In this work, GaN δ -doped with non-magnetic main group s -block elements K and Ca as digital magnetic heterostructures were purposed and explored theoretically. We found that K- and Ca-embedded GaN digital alloys exhibit spin-gapless and half-metallic ferromagnetic characteristics, respectively. All compounds obey the Slater–Pauling rule with diverse electronic and magnetic properties. For these digital ferromagnetic heterostructures, spin polarization occurs in nitrogen within a confined space around the δ -doped layer, demonstrating a hole-mediated two-dimensional magnetic phenomenon.