Study of hyperfine interactions in nano structured In2O3 system by perturbed angular correlation spectroscopy using 111Cd as nuclei probe

Full text: Among the numerous metallic oxides, indium oxide is intensively studied because of its various applications, including optical-electronic and electrochemical devices. Recently, numerous efforts have been directed to improve nano- and micro-structures to gas sensor. This study requires techniques with high sensitivity in nanoscale able to verify that the crystallites present in the nano-particles have many defects and structure appropriate to maintain its properties without deterioration. In this work, a nuclear technique called Perturbed gamma-gamma Angular Correlation (PAC) which uses a nuclear probe to measure hyperfine interactions was used to measurement the electric quadrupole interaction. Here it was used 111In (111Cd) probe which decays through the gamma cascade 171-245 keV where nuclear properties of the intermediate level are well known - 111Cd: t1/2 = 84.5 ns, quadrupolar moment (Q) is 0.83 b and dipolar moment μ = -0.76 μN. Nanostructured In2O3 power pure and doped with nickel (Ni) were prepared by the Pechini sol-gel method, annealed until 973 K for 10h and investigated by PAC. The PAC measurements were carried out with a conventional slow-fast coincidence set-up with four conical Baf2 detectors. A small tubular furnace was used for heating the sample while a cryogenic system was used to cool. The use of these nuclear techniques with radioisotopes allowed us to investigate the structure of crystallites and the existence of defects in nanostructured materials both in terms of its electromagnetic nature. (author)