Electronic Structure Study of Ni/Al2O3/Ni from First-Principles
The electronic structure and magnetic properties of Ni/Al2O3/Ni tunnel junctions with O-terminated and Al-terminated interface models are investigated by first-principles discrete variational method with the local-spin-density approximation. The results show that the interface atomic has an important effect on interface electronic state and spin polarization as well as TMR ratio. For the O-terminated and Al-terminated interface models, spin polarization at Fermi level of Ni layers exhibit negative. It is found that absolute value of spin polarization as well as TMR ratio of Al-terminated interface models is much larger than that of O-terminated interface, which shows over-oxidization of Al layer could deteriorate magnetoresistance properties.
Wei Pan and Jianghong Gong
J. X. Shang and M. Q. Guo, "Electronic Structure Study of Ni/Al2O3/Ni from First-Principles", Key Engineering Materials, Vols. 336-338, pp. 2540-2542, 2007