Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films

M. SIRENA; A. ZIMMERS; N. HABERKORN; E. KAUL; L. B. STEREN; J. LESUEUR; T. WOLF; Y. LE GALL; J.-J. GROB; G. FAINI

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Año: 2010 vol. 107 p. 113903 - 113906

0021-8979

We have investigated the influence of point defect disorder in the electronic properties of manganite films. Real-time mapping of ion irradiated samples conductivity was performed through conductiveatomic force microscopy (CAFM). CAFM images show electronic inhomogeneities in the sampleswith different physical properties due to spatial fluctuations in the point defect distribution. Asdisorder increases, the distance between conducting regions increases and the metal-insulatortransition shifts to lower temperatures. Transport properties in these systems can be interpreted interms of a percolative model. The samples saturation magnetization decreases as the irradiation dose increases whereas the Curie temperature remains unchanged.