Operation of ferroelectric plasma sources in a gas discharge mode

Abstract

Ferroelectric plasma sources in vacuum are known as sources of ablative plasma, formed due to surface discharge. In this paper, observations of a gas discharge mode of operation of the ferroelectric plasma sources (FPS) are reported. The gas discharge appears at pressures between ∼20 and ∼80 Torr. At pressures of 1–20 Torr, there is a transition from vacuum surface discharge to the gas discharge, when both modes coexist and the surface discharges sustain the gas discharge. At pressures between 20 and 80 Torr, the surface discharges are suppressed, and FPS operates in pure gas discharge mode, with the formation of almost uniform plasma along the entire surface of the ceramics between strips. The density of the expanding plasma is estimated to be about 1013 cm−3 at a distance of 5.5 mm from the surface. The power consumption of the discharge is comparatively low, making it useful for various applications. This paper also presents direct measurements of the yield of secondary electron emission from ferroelectric ceramics, which, at low energies of primary electrons, is high and dependent on the polarization of the ferroelectric material.

Enhancements of electric field and afterglow of non-equilibrium plasma by Pb(ZrxTi1−x)O3 ferroelectric electrode

“…These two electrodes were separated by a 5 mm distance and were placed into a rectangular quartz cell. The ferroelectric layer uses lead zirconate titanate (Pb(Zr x Ti 1− x )O 3 , PZT), which is a ceramic perovskite material with a tetragonal crystal structure (under T c ≈ 320 °C), and the asymmetric locations of the cations and anions result in the separation of positive and negative charge centers inside the unit cell and equip PZT with spontaneous polarization nature 25 . The high purity of the PZT material in this study is confirmed by the X-ray diffraction pattern in Supplementary Fig.…”

“…Unfortunately, only a few studies have been conducted to understand the effect of ferroelectric materials on plasma properties and dynamics. For example, electrical properties, including voltages and currents 23 and discharge patterns of both gas 24 and surface 25 , 26 were preliminarily characterized in FBD plasmas. Other studies mainly focused on practically applying ferroelectric materials to improve plasma manufacturing yield (e.g., ammonia synthesis 27 , 28 , NO x removal 29 , and carbon dioxide conversion 30 ).…”

Characterization of a Ferroelectric Atmospheric Pressure Plasma Source

“…These studies revealed plasma densities of 10 12 cm −3 and temperatures of 2-3 eV. Later, ferroelectric sources operating in the gas discharge mode were studied at higher pressures between 20 and 80 torr [25]. Two additional phenomena have been found to improve the characteristics of emission from ferroelectric ceramics, the deposition of thin films [22], [26], and the use of RF to repetitively apply an electric field [26].…”