Study On The Preparation Of Epsilon ?-Fe_2?3N On Sa And GaN Substrates By Magnetron Sputtering

Fe-N compound material is a typical magnetic material,which has a broad application prospect in magnetic storage and magnetic electronic devices.Among them,?-Fe_2?3N materials have room temperature ferromagnetism.In particular,the magnetic properties of the?-Fe_2?3N materials will change with the ratio of Fe:N.Also,the tunability of its magnetic properties has attracted people's attention.In this paper,c-axis oriented?-Fe_2?3N films were prepared on sapphire?Sa?and gallium nitride?GaN?substrates by magnetron sputtering.This paper also studied the microstructure,surface morphology,component properties and magnetic properties of?-Fe_2?3N films which were prepared at different temperatures and different substrates.The results show that:For samples prepared at different reaction temperatures,the product only has a cubic phase of?''-FeN and a cubic phase of?-Fe when the temperature is lower?room temperature,100??.When the reaction temperature rises to 200°C,hexagonal?-Fe_2?3N starts to form.The?-Fe_2?3N will generate with the temperature increasing to 300°C and 400°C.Especially when the reaction temperature is 400°C,a c-axis oriented single crystal?-Fe_2?3N thin film is prepared.And the ratio of Fe:N in the thin film sample can be controlled by regulating the ratio of nitrogen/argon flow.The c-axis oriented single crystal?-Fe_2?3N film were prepared on a sapphire?Sa?substrate at higher temperature?400°C?and lower nitrogen flow rate?partial pressure?.The crystal lattice structure and the lattice matching pattern of the?-Fe_2?3N/Al₂O₃ interface can be clearly seen in the high resolution transmission electron microscope because of the good quality of the single crystal thin film.The analysis of chemical environment shows that the sample surface has a very thin oxide layer.With the deepening of the analysis depth,we only observed the binding energy characteristics of Fe2p and N1s in?-Fe_2?3N.We also conformed the binding energy of Fe2p and N1s.The magnetic characterization shows that the samples prepared at different nitrogen flow rates have both ferromagnetism,paramagnetism and diamagnetism.The diamagnetism is caused by the substrate while the ferromagnetism and paramagnetism are caused by?-Fe_2?3N.Those anslysis are consistent with the component analysis.Samples prepared on GaN substrates at higher temperatures?400°C?have similar structural characteristics and surface morphology to those prepared on Sa substrates.This is mainly due to the lower lattice mismatch in the c-plane.In this paper,the c-axis oriented single-crystal?-Fe_2?3N thin films have been prepared for the first time in the world.Their basic characteristics have also been analyzed.Next,in-depth study of their spin transport will be started and their application prospects in the field of spintronic devices will be explored.