Magnetic properties of epitaxial CrN films

The authors have investigated the structural and magnetic properties of CrN films grown on MgO(001) and sapphire(0001) by rf-plasma-assisted molecular beam epitaxy. Cr N ∕ Mg O ( 001 ) exhibits a better epitaxial quality than CrN/sapphire(0001). The Cr N ∕ Mg O film shows clear paramagnetic behavior at low temperatures, whereas CrN/sapphire exhibits a ferromagneticlike response with an order temperature above room temperature which resembles the magnetic behavior found in Cr-doped dilute magnetic semiconductors. Keeping in mind that bulk CrN exhibits antiferromagnetic behavior, the dramatically different magnetic behaviors found in epitaxial CrN films grown on MgO and sapphire demonstrate the importance of epitaxial constraints in determining their magnetic properties.