Search results

Sort By:

Limit search:

Ion flux's pressure dependence in an asymmetric capacitively coupled rf discharge in NF3

100%

Mateev E., Zhelyazkov I.

Open Physics

2004

vol. 2

issue 1

1-11

Starting from an analytical macroscopic/phenomenological model yielding the self-bias voltage as a function of the absorbed radio-frequency (rf) power of an asymmetric capacitively coupled discharge in NF3 this paper studies the dependence of the ion flux onto the powered electrode on the gas pressure. An essential feature of the model is the assumption that the ions' drift velocity in the sheath near the powered electrode is proportional to E α, where E=−ΔU (U being the self-bias potential), and α is a coefficient depending on the gas pressure and cross section of elastic ion-neutral collisions. The model also considers the role of γ-electrons, stochastic heating as well as the contribution of the active electron current to the global discharge power balance. Numerically solving the model's basic equations one can extract the magnitude of the ion flux (at three different gas pressures) in a technological etching device (Alcatel GIR 220) by using easily measurable quantities, notably the self-bias voltage and absorbed rf power.

Electrical characteristics of HTS/manganite double layers

52%

Nurgaliev T., Štrbík V., Miteva S., Blagoev B., Mateev E., Neshkov L., Beňačka Š., Chromik Š.

Open Physics

2007

vol. 5

issue 4

637-649

Superconductor/ferromagnetic (SC/FM) Y1Ba2Cu3O7−δ /La0.7Sr0.3MnO3 (YBCO/LSMO) double layers were prepared on LaAlO3 substrates by magnetron sputtering and their electrical and microwave parameters were investigated at 77 K. In the theoretical plan, simple formulas for estimation of the sensitivity of the SC surface impedance to the concentration changes of normal charge carriers were proposed and the surface resistance R S peculiarities of both SC and FM surfaces were described. Thinner YBCO/LSMO structure was characterized by lower SC parameters and higher surface resistance R S at ∼ 4 GHz. The difference of R S of sample SC surfaces was interpreted as due to a difference between the normal charge carrier densities in these samples. R S of the FM surface was higher than that of the SC surface due to the microwave losses of the magnetic subsystem. A peak of the microwave losses, observed in the thicker double layer, was assumed to be caused by uniform FMR in the LSMO film.

Refine search results

2 Open Physics

1 2007

1 2004

2 Mateev E.

1 Beňačka Š.

1 Blagoev B.

1 Chromik Š.

1 Miteva S.

1 Neshkov L.

1 Nurgaliev T.

1 Zhelyazkov I.

1 Štrbík V.

Search results

Ion flux's pressure dependence in an asymmetric capacitively coupled rf discharge in NF3

Electrical characteristics of HTS/manganite double layers