L. A. Errico

APPEARANCE OF ROOM-TEMPERATURE FERROMAGNETISM IN CU-DOPED TIO2-DELTA FILMS

In recent years there has been an intense search for room temperature ferromagnetism in doped dilute semiconductors, which have many potentially applications in spintronics and optoelectronics. We report here the unexpected observation of significant room temperature ferromagnetism in a semiconductor doped with nonmagnetic impurities, Cu-doped TiO

Local structure and magnetic behaviour of Fe-doped TiO2 anatase nanoparticles: experiments and calculations

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Metal impurities in an oxide: Ab initiostudy of electronic and structural properties of Cd in rutileTiO2

thin films grown by Pulsed Laser Deposition. The magnetic moment, calculated from the magnetization curves, resulted surprisingly large, about 1.5

The role of vacancies, impurities and crystal structure in the magnetic properties of TiO2

\mu_B

Study of the relation between oxygen vacancies and ferromagnetism in Fe-doped TiO2 nano-powders

per Cu atom. A large magnetic moment was also obtained from ab initio calculations using the supercell method for TiO

Electric-Field Gradient at Cd Impurities in In2o3. A FLAPW Study

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FLAPW Study of the EFG Tensor at Cd Impurities in In2O3

with Cu impurities, but only if an oxygen vacancy in the nearest-neighbour shell of Cu was present. This result suggests that the role of oxygen vacancies is crucial for the appearance of ferromagnetism. The calculations also predict that Cu doping favours the formation of oxygen vacancies.

Hyperfine interactions at 181Hf(→181Ta) impurities implanted in Er2O3 and Gd2O3: structural and electronic dependence of the EFG in bixbyite sesquioxides

We present an investigation of Fe-doped TiO2 anatase nanoparticles (2.8 and 5.4 at.% Fe) where Fe substitutes Ti atoms without the presence of other phases. In order to characterize these samples we used x-ray absorption experiments, 57Fe Mossbauer spectroscopy, ab initio calculations and magnetometry. Results from iron K-edge near-edge and extended x-ray absorption fine structure confirm that Fe3+ replaces Ti4+ in the TiO2 anatase structure increasing the metal-anion bond length. Mossbauer spectra recorded at room temperature show asymmetric Fe3+ broad doublets. These results agree with structural, hyperfine and magnetic properties calculated using density-functional theory, if oxygen vacancies are present in the iron–oxygen octahedra. Mossbauer and magnetic measurements indicate that samples are paramagnetic at room temperature. At low temperatures, two kind of magnetic species can be distinguished: (i) isolated paramagnetic Fe3+ ions and (ii) antiferromagnetically coupled Fe3+ ions. These results also show that substitutional Fe in nanosized anatase TiO2 does not induce ferromagnetic ordering.

FP-LAPW Calculations of the EFG at Cd Impurities in Rutile SnO2

In this work we undertake the problem of a transition metal impurity in an oxide. We present an ab initio study of the relaxations introduced in

NON-IONIC CONTRIBUTIONS TO THE ELECTRIC-FIELD GRADIENT AT 111CD/181TA IMPURITIES IN BIXBYITES

{\mathrm{TiO}}_{2}