Ferromagnetnormalmetal

Ferromagnetnormalmetal is a term used to describe the interface or stack formed by a ferromagnetic metal in contact with a non-magnetic (normal) metal. It is a foundational element in spintronics, where the spin degree of freedom of conduction electrons is exploited. In such systems, a spin-polarized current originating in the ferromagnet enters the normal metal, creating a non-equilibrium spin accumulation that decays over a characteristic spin diffusion length in the metal.

Transport across the interface is governed by the interfacial properties, including spin-dependent transmission, reflection, and the spin-mixing conductance. The proximity of the ferromagnet can induce a small magnetic moment in the adjacent normal metal (the magnetic proximity effect), and interfaces can also exhibit spin-memory loss that randomizes spin orientation upon transmission.

Spin transport in F/N structures is analyzed with diffusion models (e.g., the Valet-Fert formalism) describing how spin polarization relaxes in the normal metal and how backflow of spins affects current. Spin currents generated in such structures can exert spin-transfer torques on the ferromagnet and can drive phenomena like spin pumping, where precessing magnetization pumps spin current into the normal metal.

Materials commonly used include ferromagnets such as iron, cobalt, or nickel, and normal metals like copper, aluminum, or silver. The F/N interface is also central to experiments on nonlocal spin valves and to studies of magnetoresistance arising from spin-dependent scattering.

Applications span magnetic memory, sensing, and basic studies of spin coherence. The concept also extends to related heterostructures where the normal metal hosts additional materials or spin-orbit effects that couple to the ferromagnet.