NiCuNi

NiCuNi is a trilayer thin-film stack composed of nickel, copper, and nickel. In this context, Ni and Cu refer to elemental nickel and copper deposited as consecutive layers, often at nanometer-scale thicknesses on a substrate.

Structure and properties: Outer layers are nickel, a ferromagnetic metal with a Curie temperature of about 358 C, while the middle copper layer is non-magnetic and highly conductive. The copper spacer mediates exchange coupling between the two nickel layers, which can be ferromagnetic or antiferromagnetic depending on the spacer thickness and deposition conditions. This coupling affects the magnetic configuration and electrical resistance of the stack.

Fabrication and variants: NiCuNi films are typically produced by magnetron sputtering or electron-beam evaporation in high vacuum, sometimes with seed layers for adhesion. They are often capped with another layer to prevent oxidation (e.g., Ta, Al or Pt). The NiCuNi stack can be integrated into microfabricated devices or structured into patterned elements.

Applications: The NiCuNi trilayer is studied in magnetism and spintronics as a simple model system for exchange coupling and magnetoresistive effects. Potential uses include magnetic sensors, spin-valve structures, and prototyping components for MRAM or magnetic read-head technologies.

See also: exchange coupling, spin valve, nickel, copper, magnetic multilayers.