| AVS 56th International Symposium & Exhibition | |
| Magnetic Interfaces and Nanostructures | Wednesday Sessions |
| Session MI+EM-WeA |
| Session: | Magnetism and Spin Injection in Semiconductors |
| Presenter: | J. Tang, University of Wyoming |
| Authors: | X. Wang, University of Wyoming K. Fox, University of Wyoming W. Wang, University of Wyoming J. Tang, University of Wyoming M.J. An, University of Nebraska-Lincoln K. Belashchenko, University of Nebraska-Lincoln P.A. Dowben, University of Nebraska-Lincoln |
| Correspondent: | Click to Email |
Methods to prepare EuO thin films reported in the literature include reactive thermal evaporation of Eu in the presence of oxygen gas and molecular beam epitaxy (MBE). We have successfully prepared single phase polycrystalline and epitaxially grown EuO and Gd-doped EuO via pulsed laser deposition (PLD) using metal targets. This opens a new route to the preparation of this interesting material with high quality. Samples prepared in vacuum exhibit the typical M(T) curve for a ferromagnet and have a Curie temperature of 70 K. When the samples were grown under ultrahigh purity H2 flow, they show the “double-dome” feature characteristic of oxygen deficient EuO. Tc as high as 150 K has been observed for EuO. The increased Curie temperature is attributed to the magnetic coupling enhanced by the 4f-5d coupling between the Eu moments and doped electrons. Our results reaffirm that oxygen vacancies alone can substantially increase the Tc. Calculations on the phase diagram (for Gd+EuO), the effects of oxygen vacancies and associated band structures and density of states will be presented.