“Defects Studies In Pure And Dopped In2O3 Single Crystals By TPAC”

R.A.QUILLE RAMOS; L. C. DAMONTE; A.F. PASQUEVICH

Congreso; HFI/NQI 2010; 2010

The indium oxide electronic properties, pure or impurity doped, as massive material or thin films, irrespective of its morphology, i.e. nanoparticles or nanowires, are of high interest due to their potential technological applications. Perturbed Angular Correlations (PAC) measurements on pure and dopped In2O3 using 111In as radioactive probe are presented. In a PAC experiment the interaction between the quadrupolar moment of the excited nuclear state of 111Cd (resultant isotope after the EC desexcitation of 111In) and the electric field gradient (EFG) originated in the probe neighborhood is investigated. This nuclear disintegration offers an original method of doping, introducing acceptors donors in the starting material. These impurities ions can act with different charge states which depend on different factors. In particular, the so known “after effects” (AE), which appears after the nuclear transition 111In  111Cd by EC, were, two decades ago, qualitatively related to electronic availability around the probe atom. Although since then great amount of experimental data were collected , the description of this phenomenon was not yet well understood. Moreover it is difficult to predict the conditions under which AE can occur. In the present work we pretend to give a detail description of the AE, experimental data available in literature is revised and results on In2O3 single crystal grown by high temperature thermal treatments from graffito and indium mixtures are analyzed.