Magnetic properties of Gd-substituted yttrium nitride.

Gd sub x Y sub (1-x) N is an instantiation of the broad series of diluted magnetic materials composed of lanthanide nitrides in a Sc, Y or La nitride host. These lanthanoid nitrides are interstitial compounds which all form in the B1 structure and with similar lattice constants, so solid solutions are readily obtained. We have prepared single-crystal thin films by epitaxial growth on sapphire substrates, and obtained material with moderate carrier densities (n sub (Hall) ~ 10 sup (21) cm sup (-3)) and mobilities (mu sub (Hall) ~ 10 cm sup 2 V sup (-1) sec sup (-1)). Below the ordering temperature T sub c ~15 K the Gd sub x Y sub (1-x) N films (0.250.40) exhibit a ferromagnetic- like M-H loop. The saturation magnetization measured at 15 KOe and 4.2 K is anomalously low, representing an effective moment of only 4.2 mu sub B per Gd compared to the expected value of at least 7.2 mu sub B.