Pulsed deposition technique

The studies of electrodeposited multilayer materials to date show clearly that electrodeposition is a feasible technique for the production of thin multilayered materials in systems that from an electrochemical standpoint are adaptable to the pulsed deposition technique. 

The yields of photolysis products depend mainly on the conditions for matrix-formation (concentration, deposition technique, rate of deposition, annealing, etc.). Such conditions should be controlled adequately in accordance with the selectivity and efficiency required in proposed synthetic applications. The stratified matrix formation by pulsed deposition technique can be employed as a useful means for elucidation of the detailed mechanisms of reactions between cocondensed species. 

First ac electrodeposition of Cu, Ni, Co, and Sn was reported in [2,3]. However there was no any detail analysis of the regimes used for the deposition. In this work we developed a pulsed deposition technique by taking into account transients observed under anodic and cathodic pulses. 

Using pulse plating techniques with a duty cycle of 50%, it is also possible to produce crack-free chromium deposits from a sulphate- or silicofluoride-catalysed solution with a hardness similar to deposits obtained by direct currenf . A high frequency (2 000-3 000 Hz) is required to give the hardest deposits at a current density of 40 A/dm and a temperature of 54°C. It is important to avoid conditions that will co-deposit hydrides. 

Pulse plating techniques with symmetric or asymmetric waves have been employed for improving the deposition of CdS in acidic aqueous baths of cadmium sulfate and thiosulfate precursors [46, 47], A better control of sulfur incorporation in the deposits was reported. 

This pulse plating technique has the advantage of simplicity, i.e., application of a simple waveform in current or potential in a single solution. Problems arise, however, because at the more positive potential a pure element or compound is deposited, while during the pulse the second element or compound formed is inevitably contaminated with the first. Switzer et al. [73] reported a variation on... 

Schubert J, Schdning MJ, Schmidt C, Siegert M, Mesters St, Zander W, Kordos P, Liith H, Legin A, Mourzina YG, Seleznev B, Vlasov YG (1999) Chalcogenide-based thin film sensors prepared by pulsed laser deposition technique. Appl Phys A Mater Sci Process 69 803-805... 

Pulsed field gel electrophoresis, 9 746 Pulsed flashlamps, 14 619 Pulsed laser deposition chamber, 24 739 Pulsed laser deposition (PLD), 24 738-743 advancement of, 24 739 as an alternative deposition technique, 24 742-743... 

Pulsed laser ablation deposition technique (PLAI) technique)... 

Geography, Geology Pulse/echo techniques are used in the location of mineral and oil deposits and in depth gauges for seas and oceans. Echo ranging at sea has been used for many years (SONAR). 

Other coating processes involving fluoridated apatite have been investigated to improve the long-term adhesion and promote osteointegration of cementless titanium-based metal implants pulsed laser deposition, electron beam deposition and ion beam sputter deposition techniques, and sol-gel methods, for example. They lead to fluor-containing calcium phosphates (apatites in most cases) with different compositions and crystallinity states. 

RE-TM-based films. - The deposition techniques (sputtering or PLD - pulsed laser deposition) have been used successfully to prepare SmCo5 and Nd2Fel4B nanoparticles [38, 39]. After room temperature deposition, the nanoparticles are amorphous. The desired crystal structure and magnetic properties are obtained through application of a post-deposition annealing treatment. Due to the high reactivity of the materials, this constitutes a non trivial task. 

ZnO thin films can be prepared by a variety of techniques such as magnetron sputtering, chemical vapor deposition, pulsed-laser deposition, molecular beam epitaxy, spray-pyrolysis, and (electro-)chemical deposition [24,74]. In this book, sputtering (Chap. 5), chemical vapor deposition (Chap. 6), and pulsed-laser deposition (Chap. 7) are described in detail, since these methods lead to the best ZnO films concerning high conductivity and transparency. The first two methods allow also large area depositions making them the industrially most advanced deposition techniques for ZnO. ZnO films easily crystallize, which is different for instance compared with ITO films that can... 

Pulsed electron beam deposition (PED) Pulsed electron beam source emitting 100 ns long electron pulses with 10-20 keV and kA intensity into the deposition chamber, no excimer laser is required, innovative complimentary technique to PLD, further extending the range of materials to be grown as thin films by pulsed energy techniques [128,135]... 

Fig. 8.6 Features of the double-pulse technique Model on the influence of the transition moment between nucleation pulse and growth pulse in the course of the double-pulse deposition on the Gaussian particle distribution formed after the nucleation pulse [29] (a) Gaussian particle distribution of N nuclei with radii r > tcr (T)i) for different over potentials of the first pulse ( t ib << t iAl)- The hatched area of the Gaussian distribution corresponds to the number of stable particles with radii r > rcr (tje). whereas the white area of particles of under critical size is amputated as these particles dissolve, (b) Representation of the result of the particle cut off, small (dark) particles dissolve but larger particles (white) survive under the lower overvoltage of the growth pulse.(c) If a small particle lies in the diffusion zone of a larger particle the under saturation can favor the dissolution of the smaller ones...

The Co particles were synthesized by the chemical deposition techniques from C0SO4 7 H2O solutions. The samples were characterized by TEM, X-Ray spectrometry and diffractometiy (DRON - SEIFERT-RM4). For investigation of nearest topological and chemical neighboring of Co atoms the NMR technique was used. The NMR spectra were measured by standard pulse spin-echo... 

G. K. Hubler, Comparison of vacuum deposition techniques, Pulsed Laser Deposition Thin Films 327-55, 327, 1994. 

Powder CdSe nanopartides prepared by a pulsed sonoelectrochemical technique with a sonoelectrochemical device similar to that described by Reisse, namely the sonoelectrode , were reported first by Mastai et al. [150]. In Figure 6.8 we present the experimental set-up for pulsed sonoelectrochemical deposition of CdSe nano-particles, namely the sonoelectrode , and schematics of the sonic and electrochemical waveforms. 

A pulse reaction technique was used to study (1) the behavior of the catalysts in the first step of the reaction, (2) the initial carbon deposition and, (3) the effects of carbon deposition on conversion and selectivity. Experiments were carried out at 853 K by injecting pulses of pure propane (pulse volume 0.50 cm 8TP) to the catalytic bed, which was maintained under flowing He (30 ml min ) between two successive pulses. The samples were previously reduced for 3h at 853 K under flowing H2. The reaction products were analyzed in a FID chromatographic system with a packed column (Porapack Q). 

Electrodeposition is an elegant and efficient technique for the production of nano-objects. Using the pulse deposition mode, it is possible to control the amount of atoms to be deposited with great precision. That is, pulsing with pulse durations of a few milliseconds to a few seconds, allows the deposition of clusters of atoms or layers with thickness of a few to hundreds of nanometers. 

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