Ferromagnetism in GaAs structures with Mn-delta-doped layers

It is established that GaAs-based semiconductor heterostructures containing a single layer delta-doped with manganese, obtained by combining the methods of metalorganic chemical vapor deposition (MOCVD) in a hydride system and laser ablation of solid targets in a common technological cycle, possess ferromagnetic properties. The structures demonstrate nonlinear magnetic-field dependences of the Hall resistance with a hysteresis (at a coercivity of about 80 Oe) and show a negative magnetoresistance (up to 4% in a magnetic field of 3000 Oe) at temperatures below the Curie point ($T_C\approx$ 30 K).