scholarly journals Effect of Peak Current Density on Inner-wall Deposition of Ti Films by High-power Impulse Magnetron Sputtering

2020 ◽  
Vol 63 (8) ◽  
pp. 404-412
Author(s):  
Hidetoshi KOMIYA ◽  
Yoshikazu TERANISHI ◽  
Ana B. CHAAR ◽  
Ming YANG ◽  
Tetsuhide SHIMIZU
Keyword(s):  
Magnetron Sputtering ◽  
Current Density ◽  
High Power ◽  
Peak Current Density ◽  
Peak Current ◽  
Wall Deposition ◽  
Ti Films

Influence of peak current on substrate plasma sheath properties of Ti films deposited by high-power pulsed magnetron sputtering

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940016
Author(s):  
C. Z. Chen ◽  
D. L. Ma ◽  
N. Huang ◽  
Y. X. Leng
Keyword(s):  
Magnetron Sputtering ◽  
Equivalent Circuit ◽  
Plasma Density ◽  
High Power ◽  
Equivalent Circuit Model ◽  
Film Structure ◽  
Circuit Model ◽  
Plasma Sheath ◽  
Peak Current ◽  
Pulsed Magnetron

For film deposition, the substrate sheath properties, such as the plasma density, ion-to-atom ratios around the substrate, are more important for the film structure. In this paper, titanium thin films were deposited on grounded substrates by high-power pulsed magnetron sputtering (HPPMS) with the peak current in the range of 113–185 A. A simple and new equivalent circuit model of the sheath was established to study the plasma density around the substrate sheath. The Ti ion-to-atom ratios near substrate were studied by optical emission spectroscopy (OES), and the film structure was detected by transmission electron microscopy (TEM). The results showed that the calculated plasma density was from 0.8 × 10[Formula: see text] to 1.4 × 10[Formula: see text] m[Formula: see text] at different peak current. These were consistent with the results measured by a modified one-grid ion collector using saturation current probe method, which proved our proposed equivalent circuit model was correct. The Ti ion-to-atom ratios around the substrate were estimated at about 24%–62%. The plasma density and ion to atom ratio around the substrate increased with the peak current, and this could lead to a higher film crystallization and preference growth on Ti (101) and (100).

THE EFFECT OF PREPARED PARAMETERS ON THE MICROSTRUCTURE OF ELECTRODEPOSITED NANOCRYSTALLINE NICKEL COATING

2004 ◽  
Vol 11 (04n05) ◽  
pp. 433-442 ◽  
Author(s):  
C. Y. DAI ◽  
Y. PAN ◽  
S. JIANG ◽  
Y. C. ZHOU
Keyword(s):  
Grain Size ◽  
Surface Morphology ◽  
Current Density ◽  
Crystal Orientation ◽  
Nickel Coating ◽  
Pulse Frequency ◽  
Lattice Parameter ◽  
Nanocrystalline Nickel ◽  
Peak Current Density ◽  
Peak Current

The nanocrystalline nickel coating was synthesized by pulse-jet electrodeposition from modified Watts bath. Pulse and jet plating was employed to increase the deposition current density, decrease diffusion layer, increase the nucleation rate and in this case the prepared method would result in fine-grained deposits. Transmission and scanning electron microscopy and X-ray diffraction (XRD) were used to study the microstructure, the surface morphology, the crystal preferred orientation and the variety of the lattice parameter respectively. The influence of pulse parameters, namely peak current density, the duty cycle and pulse frequency on the grain size, surface morphology, crystal orientation and microstructure was studied. The results showed that with increasing peak current density, the deposit grain size was found to decrease markedly in other parameters at constant. However, in our experiment it was found that the grain size increased slightly with increasing pulse frequency. For higher peak current density, the surface morphology was smoother. The crystal orientation progressively changed from an almost random distribution to a strong (111) texture. This means that the peak current density was the dominated parameter to effect the microstructure of electrodeposited nanocrystalline nickel coating. In addition, the lattice parameter for the deposited nickel is calculated from XRD and it is found that the calculated value is less than the lattice parameter for the perfect nickel single crystal. This phenomenon is explained by the crystal lattice mismatch.

Microstructure Evolution of As-Cast Nickel Aluminum Bronze under Electropulsing

2020 ◽  
Vol 861 ◽  
pp. 28-34
Author(s):  
Jie Fang ◽  
Guo Lin Song ◽  
Wei Liu ◽  
Qiu Lin Li
Keyword(s):  
Microstructure Evolution ◽  
Current Density ◽  
Phase Region ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Peak Current Density ◽  
Peak Current ◽  
Β Phase ◽  
Nickel Aluminum Bronze ◽  
Electropulsing Treatment

In this work, the microstructure evolution of as-cast NAB under different electropulsing parameters were studied. The microstructure of the electropulsing treatment (EPT) sample was characterized by mircohardness test and optical microscopy. The results show that compared with heat treatment, when the peak current density reaches 5.84×108A/m2 (no significant change in the structure when the peak current density is lower), the β' phase region undergo phase transition in a shorter time. When the peak current density reaches 7.25×108A/m2, the sample is significantly affected by the Joule heating effect, and the κⅢ and κⅣ phases are successively dissolved to form Widmanstätten α structure. As the β' phase increases and the Widmanstätten α structure forms, the hardness value of the microstructure increases by 80%.

scholarly journals Dravet Variant SCN1AA1783V Impairs Interneuron Firing Predominantly by Altered Channel Activation

2021 ◽  
Vol 15 ◽  
Author(s):  
Nikolas Layer ◽  
Lukas Sonnenberg ◽  
Emilio Pardo González ◽  
Jan Benda ◽  
Ulrike B. S. Hedrich ◽  
...  
Keyword(s):  
Current Density ◽  
Input Resistance ◽  
Epileptic Encephalopathy ◽  
Dravet Syndrome ◽  
Slow Inactivation ◽  
Loss Of Function ◽  
Peak Current Density ◽  
Channel Activation ◽  
Peak Current

Dravet syndrome (DS) is a developmental epileptic encephalopathy mainly caused by functional NaV1.1 haploinsufficiency in inhibitory interneurons. Recently, a new conditional mouse model expressing the recurrent human p.(Ala1783Val) missense variant has become available. In this study, we provided an electrophysiological characterization of this variant in tsA201 cells, revealing both altered voltage-dependence of activation and slow inactivation without reduced sodium peak current density. Based on these data, simulated interneuron (IN) firing properties in a conductance-based single-compartment model suggested surprisingly similar firing deficits for NaV1.1A1783V and full haploinsufficiency as caused by heterozygous truncation variants. Impaired NaV1.1A1783V channel activation was predicted to have a significantly larger impact on channel function than altered slow inactivation and is therefore proposed as the main mechanism underlying IN dysfunction. The computational model was validated in cortical organotypic slice cultures derived from conditional Scn1aA1783V mice. Pan-neuronal activation of the p.Ala1783V in vitro confirmed a predicted IN firing deficit and revealed an accompanying reduction of interneuronal input resistance while demonstrating normal excitability of pyramidal neurons. Altered input resistance was fed back into the model for further refinement. Taken together these data demonstrate that primary loss of function (LOF) gating properties accompanied by altered membrane characteristics may match effects of full haploinsufficiency on the neuronal level despite maintaining physiological peak current density, thereby causing DS.

Peak current density and brightness from poly(p-phenylenevinylene) based light-emitting diodes

1998 ◽  
Vol 9 (1-4) ◽  
pp. 178-182 ◽  
Author(s):  
N.T. Harrison ◽  
N. Tessler ◽  
C.J. Moss ◽  
K. Pichler ◽  
R.H. Friend
Keyword(s):  
Current Density ◽  
Light Emitting Diodes ◽  
Peak Current Density ◽  
Peak Current ◽  
Light Emitting
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