Experimental and Numerical Studies of a Tunable Plasma Antenna Sustained by RF Power

To study the model of plasma antenna, a system intended to establish and sustain plasma with RF power was described in this paper. This system was made as a modular design, a feature that facilitates changing of operating frequency, RF power. A univariate optimization algorithm was used to achieve impedance matching (coefficient< 5%) in the system, therefore some key experimental data were measured accurately. Experiments showed that there is a difference between establishing power and sustaining power of plasma, and indicated the function of the length of the plasma column vs. square root of RF power.

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Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173169 ◽

1990 ◽

Vol 48 (4) ◽

pp. 6-7

Author(s):

S.K. Streiffer ◽

C.B. Eom ◽

J.C. Bravman ◽

T.H. Geballet

Keyword(s):

Thin Films ◽

Room Temperature ◽

Deposition Process ◽

Nucleation And Growth ◽

Multilayer Structures ◽

Rf Power ◽

Oxygen Loss ◽

Transmission Electron ◽

Single Target ◽

Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

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Analysis of Sputtered Zinc Oxide Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001781 ◽

1980 ◽

Vol 38 ◽

pp. 416-417

Author(s):

T. A. Emma ◽

M. P. Singh

Keyword(s):

Electron Microscopy ◽

Zinc Oxide ◽

Piezoelectric Materials ◽

Oxide Films ◽

Optical Quality ◽

Zno Films ◽

Rf Power ◽

X Ray Diffraction ◽

Sputtered Films ◽

Zinc Oxide Films

Optical quality zinc oxide films have been characterized using reflection electron diffraction (RED), replication electron microscopy (REM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Significant microstructural differences were observed between rf sputtered films and planar magnetron rf sputtered films. Piezoelectric materials have been attractive for applications to integrated optics since they provide an active medium for signal processing. Among the desirable physical characteristics of sputtered ZnO films used for this and related applications are a highly preferred crystallographic texture and relatively smooth surfaces. It has been found that these characteristics are very sensitive to the type and condition of the substrate and to the several sputtering parameters: target, rf power, gas composition and substrate temperature.

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