Study of Electronic Structure In Ni_3Fe/Al_2O_3/Ni_3Fe Magnetic Tunnel Junction with Various Ferromagnetic Layer Thicknesses

摘要

A series models of Ni_3Fe/Al_2O_3/Ni_3Fe magnetic tunnel junction with Al-terminated interfaces have been established for investigating the influence of ferromagnetic layer thickness on the electronic structure, employing first-principle methods based on local spin-density approximation theory. The spin polarization of the interfacial Ni3Fe monolayer shows a maximum value as the thickness of ferromagnetic layer increases. The Al monolayers at the ferromagnetic/insulating interface and the O monolayer in the interior of insulating layer are also studied in terms of the change of spin polarization with the ferromagnetic layer thickness. In addition, we have found that the structure of Ni_3Fe monolayer has a great influence on the spin polarization.