Metal-insulator transition induced by postdeposition annealing in low doped manganite films

M. SIRENA,A
N. HABERKORN, M. GRANADA, L. B. STEREN, J. GUIMPEL

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Año: 2009 vol. 105 p. 33902 - 33904

0021-8979

We studied the transport and magnetic properties of low-doped manganite films after differentoxygenation processes. The oxygen content was adjusted by postdeposition annealing at differentoxygen pressures and annealing times. For all the samples we observed an increase in the Curietemperature and the remnant magnetization with the oxygen content. In general, for decreasingnumber of oxygen vacancies, samples under expansive strain become more homogeneous and theirelectrical resistivity decreases. A metal-insulator transition is induced in highly oxygenated filmsgrown on SrTiO3, probably related to a shift of the mobility edge crossing below the Fermi energy.We found that the oxygenation dynamics depend critically on the strain field induced by thesubstrates and also on the Sr doping concentration.