Metal/semiconductor hybrid system with two magnetic terms dependent on the field region

A magnetic semiconductor/metal nanocomposite with a nanostructured silicon wafer as base material and precipitated metallic nanostructures (Ni, Co, Fe, NiCo) is fabricated by wet etching of a silicon wafer and subsequent electrodeposition of a metal. The achieved hybrid material exhibits an interesting two-fold magnetism, consisting of a ferromagnetic behaviour at low magnetic fields (below the saturation magnetization MS of the deposited metal) and a further non-saturating contribution at fields above MS. In both cases a magnetic anisotropy is observed. The low-field behaviour is caused by the ferromagnetic properties of the metal-structures. With increasing magnetic field the enhancement of the non-saturating term above MS is nearly linear measured at temperatures above 80 K which opens the possibility to use this composite as magnetic high field sensor. The combination of silicon and a ferromagnetic metal renders this nanocomposite interesting for magneto-electronic devices.