Formation of metallic clusters in oxide insulators by means of ion beam mixing

The intermixing and near-interface cluster formation of Pt and FePt thin flms deposited on different oxide surfaces by means of Pt+ ion irradiation and subsequent annealing was investigated. Irradiated as well as post-annealed samples were investigated using high resolution transmission electron microscopy (HRTEM). In MgO and Y:ZrO2 covered with Pt, crystalline clusters with mean size of 2 nm and 3.5 nm were found after the Pt+ irradiation with 8x10^15 cm^-2 and 2x10^16 cm^-2 and subsequent annealing, respectively. In MgO samples covered with FePt, clusters with mean size of 1 nm and 2 nm were found after the Pt+ irradiation with 8x10^15 and 2x10^16 cm^-2 and subsequent annealing, respectively. In Y:ZrO2 samples covered with FePt, clusters up to 5 nm in size were found after the Pt+ irradiation with 2x10^16 cm^-2 and subsequent annealing. In LaAlO3 the irradiation was accompanied by a full amorphization of the host matrix and appearance of embedded clusters of different sizes. The determination of the lattice constant and thus the kind of the clusters in samples covered by FePt was hindered due to strong deviation of the electron beam by the ferromagnetic FePt.