Ferromagnetism in transparent thin films of MgO
Abstract
We show both theoretical and experimental evidences of the appearance of ferromagnetism in MgO thin films. First-principles calculations allow predicting the possibility of the formation of a local moment in MgO, provided the existence of Mg vacancies which create holes on acceptor levels near the O2p -dominated valence band. Magnetic measurements evidence of the existence of room-temperature ferromagnetism in MgO thin films. High-resolution transmission electron microscopy demonstrates the existence of cation vacancies in our samples. Finally, by applying the element specificity of the x-ray magnetic circular dichroism technique, we also demonstrate that the magnetic moments of the system arise from the spin polarization of the 2p electrons of oxygen atoms surrounding Mg vacancies.
- Publication:
-
Physical Review B
- Pub Date:
- July 2010
- DOI:
- 10.1103/PhysRevB.82.024405
- Bibcode:
- 2010PhRvB..82b4405M
- Keywords:
-
- 75.70.-i;
- 61.72.Bb;
- 68.37.Og;
- 71.15.Mb;
- Magnetic properties of thin films surfaces and interfaces;
- Theories and models of crystal defects;
- High-resolution transmission electron microscopy;
- Density functional theory local density approximation gradient and other corrections