ELECTRONIC STRUCTURE AND
MAGNETISM OF DILUTED MAGNETIC SEMICONDUCTORS AND OXIDES
This research
project is focused on the Mn-Ge system, a diluted magnetic semiconductor
which has shown promising magnetic properties for applications in the field
of spin-electronics [1]. In spite of its properties, the early stages of
growth of the epitaxial layers are largely unexplored and a combination of
growth temperature, layer thickness and post growth
treatments can provide a rich scenario determined by the interplay of
magnetism and electronic properties [2,3].
Aim of the project
is to draw the phase diagram of this system by combining state-of-the-art
electron spectroscopies, including band mapping with angle-resolved
photoemission spectroscopy and magnetic circular dichroism with X-rays.
The experimental
activity will be carried out both in the Surface Science and spectroscopy
Lab of the Catholic University and at the ELETTRA synchrotron radiation
facility.
In the last few
years, we have also started a research activity on the electronic properties
of diluted magnetic oxides [4], mainly based on the TiO2-rutile host
system. This activity involves the growth by r.f.sputtering of thin films
doped with transition metals, N and C, and the experimental study of their
electronic and magnetic properties [5-8]. Ab-initio calculations of
the electronic structure of doped-TiO2, accounting for the effects of
dopants, defects, and oxygen vacancies is becoming a standard tool in
our activity, and represents one of expanding fields of our investigations.
[1] F.X. Xiu, et
al. NATURE MATERIALS 9, 337 (2010)
[2] L. Sangaletti,
et al. , PHYSICAL REVIEW B 75, 153311 (2007)
[3] A. Verdini,
PHYSICAL REVIEW B 77, 075405 (2008)
[4] M. Venkatesan
et al. Nature 430, 630 (2004)
[5] L. Sangaletti,
et al. J. Phys. Cond. Matter 18, 7643 (2006)
[6] L. Sangaletti,
et al., PHYSICAL REVIEW B 78, 075210 (2008)
[7] L. Sangaletti
et al. PHYSICAL REVIEW B 80, 033201 (2009)
[8] G. Drera, et
al. APPLIED PHYSICS LETTERS 97, 012506 (2010)
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