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In this study, high uniformity AlN thin films with varying Sc doping concentration levels were deposited on Ti (120 nm)/Si substrates. The impact of Sc doping ratio and annealing temperature on the magnetic properties of Al 1−x Sc x N were studied. This work suggests that the origin of ferromagnetism of Al 1−x Sc x N is the Al vacancies introduced by Sc ions. The amount of Al vacancies grew as the Sc doping ratio increased. According to the results of spin-polarized density of states (DOS), it is hypothesized that when the concentration of Al vacancies in Al 1−x Sc x N grows, polarized itinerant electrons exist and result a magnetic phase change. • High uniformity AlN thin films composed of nano columns with different Sc doping concentrations were deposited on Ti (120 nm) /Si substrates in this work. The room-temperature ferromagnetism of the deposited Al1-xScxN films can be observed. • Combining the magnetization hysteresis loops and X-ray photoelectron spectroscopy (XPS) of the doped AlN samples with different Sc doping concentration, this work suggests that the ferromagnetism is originated from Al vacancies which are induced by Sc ions. • According to the spin-polarized density of states (DOS), the Al1-xScxN with a high concentration of Al vacancies exhibit semi-metallic characteristics. These results suggest that the interaction between the magnetic moments belonging to neighboring ions changes from bound magnetic polaron to RKKY interaction when the concentration of Al vacancies in Al1-xScxN increases. [ABSTRACT FROM AUTHOR]

1000 nm high c-axis orientation and three dimensional textured AlN films were deposited on sapphire by reactive ion assisted sputtering and the rapid thermal annealing (RTA) was carried out at 700–900 °C for 5 min to release the film stress. Transmission electron lattice images show that the relationship of the AlN/sapphire interface is [0002] AlN //[0006] sapphire and [11-20] AlN //[1100] sapphire. The Fourier filtered images of the near substrate region suggest a thin buffer layer near the substrate, in which the atomic arrangement changes from matching sapphire lattice to AlN lattice. The buffer layer was disappeared after 900 °C RTA annealing. The Raman spectra shows the in-plane tensile stress of deposited AlN films is released by the RTA. The E 2 (high) peak of the sample annealed at 900 °C shifts by 4.4 cm−1 compared to the as-deposited sample, which illustrates the tensile stress relaxation in the annealing process. In order to prevent the occurrence of peeling caused by the long heating time, this work proposed multiple-cycle rapid thermal annealing to anticipate stress relief. [Display omitted] • Reactive ion assisted sputtering is developed to prepare three dimensional textured AlN films on sapphire. • The prepared films exhibit high c-axis orientation and three dimensional textured. • Multiple-cycle rapid thermal annealing (RTA) can effectively release the stress avoid of the peeling problem. [ABSTRACT FROM AUTHOR]

Abstract: The widespread use of crosslinked polyethylene (XLPE) in the wire and cable industry may be attributed mainly to its outstanding physical and chemical properties. However, it has been recognized that degradation of XLPE insulation during service, such as thermo-oxidation and water treeing, may lead to premature electrical breakdown of the XLPE insulation cables. Diagnostic measurements would considerably assist to distinguish between bad and still good cables. Estimation of the degree of aging is at present the most important task of diagnostic methods. This paper presents a study on the thermo-oxidation-induced changes in the dielectric properties of the thermally aged 3.3kV XLPE cables in the frequency range from 70kHz to 10MHz. [Copyright &y& Elsevier]