In recent years the ‵unbalanced′ magnetron sputter source has been shown to be an important advancement for applications requiring ion-assisted, thin film deposition. Diamondlike coatings and optical multilayers are examples of coatings which can be significantly improved by ion bombardment of the growing film. The purpose of this thesis is to develop a better understanding of the main engineering factors which determine the ultimate performance of the unbalanced magnetron. Two pieces of experimental apparatus were designed for this study. A scanning magnetometer system was constructed to measure the magnetic field pattern of the magnetrons, which allowed for a detailed analysis in terms of magnetic field lines. A multiple, plasma probe assembly was developed to measure the discharge characteristics for various unbalanced magnetron configurations. The results showed that the ion flux to the substrate was highly dependant on the development of a secondary discharge away from the target surface. The secondary discharge was generated through confinement of ionizing electrons in a magnetic bottle along the magnetron axis. The ion flux to the substrate was observed to be approximately independent of the pressure and target material but highly dependant on the discharge current and target thickness. The ion/deposition flux ratio increased with decreasing target-to-substrate distance. However, the useful deposition area decreased under these conditions as the ion currents became highly focused about the axis. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

No description available.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Alan Palevsky. / Ph.D.

Though declining in popularity over the last decade, the magnetron still has applications where portable high power is needed. This study examines the predicted performance of cylindrical microwave magnetrons using analytic lumped-spoke models based on the energy conservation principle. The analytic approach is still favoured when small computer systems are used and the overall performance of the tube is to be predicted. The magnetron elements are examined and the role they play in the overall device performance analysed. Simplified representations of these elements are used to construct a complete magnetron model. The Hartree threshold condition is reexamined and a new, more accurate analytic formulation proposed. This formulation is based on electric field strengths at the base of the magnetron spoke. The effect of the space charge on the threshold condition is included. Spoke current has been evaluated at the edge of the Brillouin hub. The resulting anode- cathode voltage performance predictions are consistent with measured results. A computer program has been written to analyse the performance predicted by this model. Models proposed by other authors are examined, and compared to this model. The resulting model has been tested by comparing predicted results to the measured performance of four slot-and-hole magnetrons. To facilitate accurate magnetron testing, a new automated triple-stub high power microwave load has been developed. The load operates at a peak power of IMW from 2,7-3,OGHZ, and allows the change of the VSWR to any value along any path within the VSWR=I, 5: I circle. The development of the triple tuner and termination is discussed in detail. A new waterload configuration which has the advantage of simple construction yet good matching characteristics is presented. Automated measurement of pulling figure and construction of Rieke diagrams is discussed. The accuracy of the complete load is compared to conventional loads currently in service in the tube industry. / Thesis (Ph.D.)-University of Natal, Durban, 1988.

Orientador: José Humberto Dias Da Silva / Banca: Marcio Medeiros Soares / Banca: Antonio Ricardo Zanatta / Banca:José Roberto Ribeiro Bortoleto / Banca: Andre Luis de Jesus Pereira / Resumo: A motivação para este trabalho foi buscar uma melhor compreensão sobre o processo de crescimento dos filmes de óxido de cobalto pela técnica de DC magnetron sputtering reativo. Os filmes de interesse foram depositados sobre substratos de sílica amorfa (a -SiO2 ), aluminato de lantânio (LaAlO3 ) e safira - c (Al2O3- c) usando diferentes valores de potência de deposição e fluxo de oxigênio . As condições de crescimento dos filmes foram analisadas utilizando simulação computacional do processo de sputtering reativo baseada no modelo de Depla, medidas da emissão óptica das espécies presentes no plasma e monitor amento da taxa de crescimento através de uma microbalança de quartzo. Os resultados de difração de raios X mostraram que em baixa potência é obtida a fase Co3O4 espinélio, enquanto que em alta potência os filmes apresentaram a fase CoO cúbica . A s simulações computacionais do processo de sputtering reativo indicaram que, quando as potências de deposição são baixas, o processo de crescimento dos filmes ocorre com o alvo no regime "envenenado" . Em contraste, altas potencias favorece m o regime metálico do alvo. Medidas de emissão do plasma de deposição mostraram que em baixa potência de deposição a intensidade da linha de emissão do oxigênio é alta, porém com o aumento da potência sua intensidade diminui e a d a linha do cobalto aumenta. O s filmes de Co 3 O 4 depositados sobre substratos cristalinos apresentaram resultados promissores . Medidas de difração de raios X de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The motivation for this work was to obtain a better understanding of the growth process of cobalt oxides by the DC magnetron reactive sputtering technique. The films were dep osited on amorphous silica (a-SiO2), lanthanum aluminate (LaAlO3) and sapphire-c (c-Al2O3) substrates using different values of deposition power and oxygen flow. The conditions of growth of the films were analyzed using the optical analysis of the species present in the plasma and the monitoring of the growth rate through a quartz microbalance. The X-ray diffraction results showed that at lower powers the Co3O4 phase was obtained, while at high er power s the films presented the CoO cubic phase. The computational simulations of the reactive sputtering process indicated that, at low deposition power, the gro wth process of the films occurs with the target in the "poisoned" regime, while in high powers it favors the metallic regime of the target. Plasma emission measurements showed that at low deposition power the oxygen intensity is high while at high power it s intensity decreases and that of cobalt increases. The Co 3 O 4 films deposited on crystalline substrates showed promising results. High - resolution X-ray diffraction measurements using synchrotron radiation indicated that the deposition of Co3O4 on c-Al2O3 resulted in epitaxial growth, in which the direction [111] is perpendicular to the surface of the c - sapphire (0001) substrates. However, the deposition on LaAlO 3 resulted in growth with str... (Complete abstract click electronic access below) / Doutor

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed January 5, 2010). PDF text: xxiv, 292 p. : ill. (some col.) ; 11 Mb. UMI publication number: AAT 3365710. Includes bibliographical references. Also available in microfilm and microfiche formats.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

No description available.

R.R. Moats. / "May 18, 1949." / Bibliography: p. 23. / Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B Dept. of the Army Project No. 3-99-10-022

L.D. Smullin [and] J.E. Bagnall. / "February 2, 1949." / Bibliography: p. 14. / Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B. Dept. of the Army Project No. 3-99-10-022.