scholarly journals Mesoscale Compositionally Modulated Nanocrystalline Ni-Fe Electrodeposits for Nanopatterning Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-8
Author(s):  
P. Egberts ◽  
G. D. Hibbard

A considerable range of surface nanostructures can be fabricated by the selective dissolution of elements or phases from metallic alloys. Selectively etched electrodeposited multilayers may find useful application in optoelectronic and MEMS devices. One issue with electrodeposited multilayers is that the fine-scale multilayer structure can often exhibit significant waviness if the band layer spacing is on the same order of magnitude as the grain size. In the present study, the mean grain size was reduced to below 10 nm in a compositionally modulated Ni-Fe alloy. Preferential etching on the electroform cross-section resulted in highly uniform and directional surface channels. The evolution of this nanopatterned surface morphology was characterized by atomic force microscopy and directional roughness parameters were obtained.

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1603-1615
Author(s):  
Chandana Pal ◽  
Isabelle Chambrier ◽  
Andrew N. Cammidge ◽  
A. K. Sharma ◽  
Asim K. Ray

In-plane electrical characteristics of non-peripherally octyl(C[Formula: see text]H[Formula: see text]- and hexyl(C[Formula: see text]H[Formula: see text]-substituted liquid crystalline (LC) double decker lanthanide bisphthalocyanine (LnPc[Formula: see text] complexes with central metal ions lutetium (Lu), and gadolinium (Gd) have been measured in thin film formulations on interdigitated gold (Au) electrodes for the applied voltage ([Formula: see text] range of [Formula: see text]. The conduction mechanism is found to be Ohmic within the bias of [Formula: see text] while the bulk limited Poole–Frenkel mechanism is responsible for the higher bias. The compounds show individual characteristics depending on the central metal ions, substituent chain lengths and their mesophases. Values of 67.55 [Formula: see text]cm[Formula: see text] and 42.31 [Formula: see text]cm[Formula: see text] have been obtained for room temperature in-plane Ohmic conductivity of as-deposited octyl lutetium (C[Formula: see text]LuPc[Formula: see text] and hexyl gadolinium (C[Formula: see text]GdPc[Formula: see text] films, respectively while C[Formula: see text]GdPc[Formula: see text] films exhibit nearly two orders of magnitude smaller conductivity. On annealing at 80[Formula: see text]C, Ohmic conductivities of C[Formula: see text]LuPc[Formula: see text] and C[Formula: see text]GdPc[Formula: see text] are found to have increased but the conductivity of C[Formula: see text]GdPc[Formula: see text] decreased by more than one order of magnitude to 1.5 [Formula: see text]cm[Formula: see text]. For physical interpretation of the charge transport behavior of these three molecules, their UV-vis optical absorption spectra in the solution and in as-deposited and annealed solid phases and atomic force microscopy study have been performed. It is believed that both orientation and positional reorganizations are responsible, depending upon the size of the central ion and side chain length.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


CORROSION ◽  
10.5006/2581 ◽  
2017 ◽  
Vol 74 (3) ◽  
pp. 312-325 ◽  
Author(s):  
Cheng Man ◽  
Chaofang Dong ◽  
Kui Xiao ◽  
Qiang Yu ◽  
Xiaogang Li

In situ atomic force microscopy, scanning Kelvin probe force microscopy, and potential pulse technology were used to study the pitting behavior induced by inclusions in AM355 martensitic stainless steel. The MnS-(Cr, Mn, Al)O duplex inclusion exhibited the highest sensitivity to the pitting corrosion with respect to the individual MnS and (Cr, Mn, Al)O inclusions. When exposed to a solution containing Cl−, the selective dissolution occurred on the sulfide segment of the duplex inclusion, leading to trenching along the oxide part. The dissolution mechanism of MnS segment in the duplex inclusion is similar to the individual MnS inclusion. The Cr depletion in the boundary layer at the inclusion/metal interface promoted the transition from metastable to stable pitting corrosion in the duplex inclusion.


2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.


2015 ◽  
Vol 830-831 ◽  
pp. 589-591 ◽  
Author(s):  
Hakikat Sharma ◽  
N.S. Negi

In the present study we prepared NiFe2O4, Ni0.95Cu0.05Fe2O4and Ni0.94Cu0.05Co0.01Fe2O4thin films by metallo-organic decomposition method (MOD) using spin coating technique. The samples were characterized by XRD. XRD patterns of thin films confirmed the formation of cubic spinel structure without any secondary phase. For microstructural analysis we characterized samples by Scanning Probe Microscope (SPM). From Atomic force microscopy (AFM), we analyzed surface morphology, calculated grain size, roughness and porosity. It has been found that grain size and roughness affected by Cu, Co substitution. After this we carried out magnetic force microscopy (MFM) on the samples. Effect of substitution on magnetic grains was observed from MFM.


1998 ◽  
Vol 546 ◽  
Author(s):  
A. A. Ayón ◽  
K.-S Chen ◽  
K. A. Lohner ◽  
S. M. Spearing ◽  
H. H. Sawin ◽  
...  

AbstractThe ability to etch deep trenches in silicon while controlling not only the profile of etched features but also the etching rate, uniformity and selectivity enable us to expand the number and scope of MEMS devices. In fact, the increase of MEMS applications in different and varied fields requiring deep silicon etching or high aspect ratio structures (HARS) has even been extended to include microturbomachinery which was recently introduced as a feasible source of power generation. Many projects also place additional demands on surface morphology. Thus, the scalloping observed on vertical walls during time multiplexed deep etching (TMDE), the roughness of horizontal surfaces exposed to the glow discharge and the radius at the bottom of etched features are also relevant. Therefore, it is important to understand not only the plasma processes involved but also the dependence of response variables on operating conditions. For this purpose we have designed, performed and analyzed sets of experiments adequate to fit quadratic models. The data was collected using interferometry, atomic force microscopy (AFM), profilometry and scanning electron microscopy (SEM). The exercise involved eight etching variables and it was conducted in an inductively coupled deep reactive ion etcher (DRIE). The mapping of the dependence of response variables on dry processing conditions produced by this systematic approach provide additional insight in the plasma phenomena involved and supply practical tools to locate and optimize robust operating conditions.


1995 ◽  
Vol 397 ◽  
Author(s):  
S.D. Harkness ◽  
R.K. Singh

ABSTRACTA thin film superlattice heterostructure composed of alternating BaTiO3 and SrTiO3 layers was grown on a thin YBa2Cu3O7 electrode templated on a (100) SrTiO3 wafer using the pulsed laser deposition method. Stranski-Krastanov nucleation of the layers was demonstrated using atomic force microscopy (AFM) when processing conditions were maintained at 6 millitorr oxygen partial pressure, and 550 °C substrate temperatures. High-resloution x-ray diffraction (HRXRD) measurements indicate that all the deformation was concentrated in the BaTiO3 layers with c/a extension to approximately 1.08. Rutherford backscattering spectroscopy (RBS) results indicate excellent crystallinity in the heterostructure. The microstructural data suggests that the theoretical critical thickness of the film has been surpassed by an order of magnitude.


1996 ◽  
Vol 439 ◽  
Author(s):  
S. Han ◽  
K. H. Yoon ◽  
K. H. Kim ◽  
H. G. Jang ◽  
S. C. Choi ◽  
...  

AbstractCopper films on Si(100) were prepared by partially ionized beam at 0 kV and 3 kV acceleration voltages in order to investigate effects of ion energy on electrical property with thickness. X-ray diffraction(XRD) pattern analysis was used to investigate crystallinity of the copper films, microstructure by Scanning electron microscope(SEM) and surface roughness by atomic force microscopy(AFM). The crystallinity of the copper films grown at the 3 kV was more (111) textured than that at the 0 kV. The copper films grown at the both conditions had nearly same grain size below a thickness of 1000 Å. The 1800 Å Cu film grown at the 3 kV was 3 times rough than that at the 0 kV. The resistivity of copper films increased due to surface and grain boundary scattering, and the change of resistivity was discussed in terms of surface roughness, grain size and film density assisted by average depositing energy.


2008 ◽  
Vol 8 (8) ◽  
pp. 4127-4131 ◽  
Author(s):  
G. S. Okram ◽  
Kh. Namrata Devi ◽  
H. Sanatombi ◽  
Ajay Soni ◽  
V. Ganesan ◽  
...  

Nanocrystalline nickel powders were prepared with grain size 'd' in the range 40–100 nm diameters through polyol method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for characterization. XRD of the prepared samples consistently matched with standard fcc structure of nickel without any impurity peak. Detailed analysis and calculations using Scherrer equation for (111) peak revealed systematic increase in line width and peak shifting towards lower diffraction 2θ angles with decrease in nickel to ethylene glycol mole ratio. Different values of d estimated from various peaks of each sample suggested associated microstrains in the nanograins. Values of d estimated from X-ray diffraction patterns were compared with those obtained from atomic force microscopy and scanning electron microscopy results, and discussed. Observed lattice expansion is explained, on the basis of a theoretical model of linear elasticity.


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