Sc 3 AlN – A New Perovskite

Sc 3 AlN with perovskite structure has been synthesized as the first ternary phase in the Sc–Al–N system. Magnetron sputter epitaxy at 650 °C was used to grow single‐crystal, stoichiometric Sc 3 AlN(111) thin films onto MgO(111) substrates with ScN(111) seed layers as shown by elastic recoil detection analysis, X‐ray diffraction, and transmission electron microscopy. The Sc 3 AlN phase has a lattice parameter of 4.40 Å, which is in good agreement with the theoretically predicted 4.42 Å. Comparisons of total formation energies show that Sc 3 AlN is thermodynamically stable with respect to all known binary compounds. Sc 3 AlN(111) films of 1.75 µm thickness exhibit a nanoindentation hardness of 14.2 GPa, an elastic modulus of 249 GPa, and a room‐temperature electrical resistivity of 41.2 µΩ cm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)