Date of this Version
JOURNAL OF APPLIED PHYSICS 109, 07B523 (2011)
Equiatomic MnAu clusters with average sizes of 4 and 10 nm are produced by inert-gas condensation. As-produced clusters are used to form both dense cluster films and films with clusters embedded in a W matrix with a cluster volume fraction of 25%. Both structure and magnetism are size-dependent. Structural analysis of the 10 nm clusters indicate a distorted tetragonal body-centered cubic structure with lattice parameters a=0.315 and c=0.329 nm. The 4 nm clusters have a partially ordered tetragonal L10 structure with lattice parameters a=0.410 nm and c=0.395 nm. Magnetic properties of the clusters show evidence at low temperatures of mixed ferromagnetic and antiferromagnetic interactions and ordering as well as paramagnetic spins. Saturation moments are as large as 0.54 μB per average Mn atom. The results are compared with earlier theoretical calculations on bulk MnAu.