Method of producing ultra-thin ferrite films

摘要

Preparation of a thin layer of binary ferrite or ternary ferrite by molecular beam epitaxy (MBE) assisted by atomic oxygen plasma, comprises selecting a substrate among monocrystalline materials; placing the substrate in a grow chamber; adjusting pressure; heating the substrate at >= 350[deg] C; simultaneously subjecting the substrate to atomic oxygen stream, to iron atom stream, and to other atom stream; controlling the stream with respect to the desired stoichiometry of the deposit; stopping the supply of the atomic oxygen and atoms, after obtaining a deposit of desired thickness. Preparation of a thin layer of binary ferrite of formula (AFe 2O 4) or ternary ferrite of formula (ABFe 2O 4) by molecular beam epitaxy (MBE) assisted by atomic oxygen plasma, comprises selecting a substrate among monocrystalline materials which retain their crystalline structure at a temperature of >= 350[deg] C; placing the substrate in a grow chamber; adjusting a pressure to a value, which allows growth by molecular beam epitaxy, in the grow chamber; heating the substrate at a temperature of >= 350[deg] C; simultaneously subjecting the substrate to atomic oxygen stream, to iron atom stream, and to other atom stream (A for a binary ferrite, A and B for a ternary ferrites); controlling the stream with respect to the desired stoichiometry of the deposit (AFe 2O 4or ABFe 2O 4), where the sum of the atom stream (iron (Fe), A and optionally B) is 0.5-6 A[deg] /minute; stopping the supply of the atomic oxygen and atoms (iron (Fe), A and optionally B), after obtaining a deposit of desired thickness, the pressure (p) of oxygen (1.33x10 -> 4>-6.66x10 -> 4>) varies gradually during the first 15 minutes of deposit, in the process. A, B : total chemical element able to be combined with Fe and O to produce a ferrite.