Search

Heusler alloy Co2FeAl was employed as ferromagnetic layers in Co2FeAl (3 nm)/Ru (x nm)/Co2FeAl (5 nm) synthetic antiferromagnet structures. The experimental results show that the structure with a Ru thickness of 0.45 nm is strongly antiferromagnetic coupled, which is maintained after annealing at 150 °C for 1 h. The structure has a very low saturation magnetization Ms of 425 emu/cm3, a low switching field Hsw of 4.3 Oe, and a high saturation field Hs of 5257 Oe at room temperature, which are favorable for application in ultrahigh density magnetic read heads or other magnetic memory devices. Crystal structure study testifies that the as-deposited Co2FeAl film is in the B2 phase. Therefore, Heusler alloys can be used to fabricate synthetic antiferromagnetic and it is possible to make “all-Heusler” spin valves or magnetic tunneling junctions with better magnetic switching properties and high magnetoresistance. [ABSTRACT FROM AUTHOR]

We report our study on the magnetic properties of -doped thin films fabricated by pulsed laser deposition technique. The -doped thin films show ferromagnetism at room temperature. The saturation magnetism increases from 0 to 2.4 emu/cc with the increasing of concentration up to 2%, and then decreases with further increasing of concentration. First-principles calculation demonstrates that the origination of ferromagnetism for -doped system is the two unpaired electrons of -2p. These unpaired electrons increase the magnetic moments which are responsible for the increasing ferromagnetism. [ABSTRACT FROM AUTHOR]

Here we report our study on the lithium-doped ZnO films prepared by sol-gel method. The films are polycrystalline wurtzite structure and the average particle size is about 50 nm. All the films are ferromagnetic, and the film with Li content of 8 at. % has the largest saturation magnetization of about 55 memu/g. The photoluminescence spectra show that the films have weak emission near ultraviolet region and strong emission in visible regions. The Li atoms in Zn sites can induce Zn vacancies and a low acceptor level in the energy gap, which are required for ferromagnetism. The first-principles calculations demonstrate that the ferromagnetism in the Li-doped ZnO originates from the induced magnetic moment of oxygen atoms in the nearest neighbor sites to Li-Zn vacancy pair. [ABSTRACT FROM AUTHOR]

We report room temperature ferromagnetism in boron-doped ZnO both experimentally and theoretically. The single phase Zn1-xBxO films deposited under high oxygen pressure by pulsed laser deposition show ferromagnetic behavior at room temperature. The saturation magnetization increases monotonically from 0 to 1.5 emu/cm3 with the increasing boron component x from 0% to 6.8%. The first-principles calculations demonstrate that the ferromagnetism in the B-doped ZnO originates from the induced magnetic moment of oxygen atoms in the nearest neighbor sites to B-Zn vacancy pairs. The calculated total magnetic moment shows an increasing trend with the boron component which is consistent with experiment. [ABSTRACT FROM AUTHOR]