Europium nitride: a novel diluted magnetic semiconductor.

摘要: Europium nitride is semiconducting and contains nonmagnetic ${\mathrm{Eu}}^{3+}$, but substoichiometric EuN has Eu in a mix of $2+$ $3+$ charge states. We show that at ${\mathrm{Eu}}^{2+}$ concentrations near 15%--20% ferromagnetic with Curie temperature as high 120 K. The ${\mathrm{Eu}}^{3+}$ polarization follows the ${\mathrm{Eu}}^{2+}$, confirming ferromagnetism intrinsic to which is, thus, novel diluted magnetic semiconductor. Transport measurements shed light on likely exchange mechanisms.