Exploring the composition, phase separation and structure of AgFe alloys for magneto-optical applications.

• Combinatorial thin film synthesis of bimetallic Ag x Fe 1−x alloy for rapid materials characterization. • Correlation of composition and structure to the optical and magnetic properties of Ag x Fe 1-x thin films. • Magnetic measurements reveal Ag x Fe 1−x has an antiferromagnetic phase Néel temperature of ≈120 K. • Controlled phase separation in immiscible Ag-Fe system results in tunable magneto-optical properties. Bimetallic alloys with large discrepancies in atomic radii and crystal structure typically yield systems that are highly immiscible, even at high temperatures. The Ag x Fe 1−x binary system has limited solid and liquid solubility and thus phase separated Ag + Fe alloys should result. Furthermore, Ag has interesting plasmonic properties and Fe is a strong ferromagnet, thus magneto-plasmonic nanoparticles/films should result due to their phase separation. We have leveraged a combinatorial sputter deposition to synthesize thin films with a large Ag x Fe 1−x (0.19 < x < 0.84) phase space to correlate the composition and structure to the optical and magnetic properties for both as-deposited and annealed compositions. [ABSTRACT FROM AUTHOR]