scholarly journals The Effect of Microstructure of Molybdenum Target

2021 ◽  
Author(s):  
Geng An ◽  
Jun Sun
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Surface Area ◽  
Grain Orientation ◽  
Deposition Velocity ◽  
Grain Structures ◽  
The Difference ◽  
Morphological Differences ◽  
Effect Of Microstructure

Abstract: Molybdenum (Mo) thin films were sputtered from two kinds of Mo targets with different microstructures under the same sputtering process, and the effect of microstructure of Mo target on morphology, deposition rate and resistance of sputtered film were studied and discussed. The results show that morphological differences between Mo thin films sputtered by Mo targets with different microstructures are very small. The more uniform and finer the grain structures of Mo target, the better the uniformity on thickness and resistance of Mo sputtered film. Moreover, during sputtering process, when Mo target’s grain size is finer and the surface area of grain boundary is higher, the thickness reduction of the target is more homogeneous and the sputtering film has faster deposition velocity. The difference in microstructure of the Mo target has not obvious influence on the grain orientation of sputtering film.

Effects of resolution on the measurement of grain ‘size’

1985 ◽  
Vol 49 (353) ◽  
pp. 539-546 ◽  
Author(s):  
R. Dearnley
Keyword(s):  
Grain Size ◽  
Image Analysis ◽  
Grain Boundary ◽  
Surface Area ◽  
Unit Volume ◽  
Fractal Dimensions ◽  
Size Analysis ◽  
Automatic Image Analysis ◽  
Fine Grained ◽  
Kinetics Of

AbstractMeasurements of fine-grained dolerites by optical automatic image analysis are used to illustrate the effects of magnification and resolution on the values obtained for grain ‘size’, grain boundary length, surface area per unit volume, and other parameters. Within the measured range of optical magnifications (× 26 to × 3571) and resolutions (1.20 × 10−3 cm to 8.50 × 10−6 cm), it is found that the values of all grain parameters estimated by chord size analysis vary with magnification. These results are interpreted in terms of the concepts of ‘fractal dimensions’ introduced by Mandelbrot (1967, 1977). For some comparative purposes the fractal relationships may be of little significance as relative changes of size, surface area, and other parameters can be expressed adequately at given magnification(s). But for many studies, for instance in kinetics of grain growth, the actual diameter or surface area per unit volume is an important dimension. The consequences are disconcerting and suggest that it may be difficult in some instances to specify the ‘true’ measurements of various characteristics of fine-grained aggregates.

Characterization of Sputtered CdTe Thin Films with Electron Backscatter Diffraction and Correlation with Device Performance

2015 ◽  
Vol 21 (4) ◽  
pp. 927-935 ◽  
Author(s):  
Matthew M. Nowell ◽  
Michael A. Scarpulla ◽  
Naba R. Paudel ◽  
Kristopher A. Wieland ◽  
Alvin D. Compaan ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Electron Backscatter Diffraction ◽  
Electrical Performance ◽  
Poor Correlation ◽  
Twin Boundaries ◽  
Electron Backscatter ◽  
Backscatter Diffraction

AbstractThe performance of polycrystalline CdTe photovoltaic thin films is expected to depend on the grain boundary density and corresponding grain size of the film microstructure. However, the electrical performance of grain boundaries within these films is not well understood, and can be beneficial, harmful, or neutral in terms of film performance. Electron backscatter diffraction has been used to characterize the grain size, grain boundary structure, and crystallographic texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with microstructure. Weak fiber textures were observed in the as-deposited films, with (111) textures present at lower deposition pressures and (110) textures observed at higher deposition pressures. The CdCl2-treated samples exhibited significant grain recrystallization with a high fraction of twin boundaries. Good correlation of solar cell efficiency was observed with twin-corrected grain size while poor correlation was found if the twin boundaries were considered as grain boundaries in the grain size determination. This implies that the twin boundaries are neutral with respect to recombination and carrier transport.

Effects Of Grain Boundaries on the Resistivity of Cosputtered Wsi2 Films

1981 ◽  
Vol 10 ◽  
Author(s):  
D. R. Campbell ◽  
S. Mader ◽  
W. K. Chu
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Reflection Coefficient ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Charge Carriers ◽  
Boundary Scattering ◽  
Grain Boundary Scattering

ABSTRACTResistivity and grain size measurements on thin films of co-sputtered WSi2 show that the resistivity in this material is dominated by grain boundary scattering. The reflection coefficient for the transport of charge carriers through the grain boundaries was determined to be approximately 0.9.

Influence of Grain Size and Grain Boundary of Workpiece on Micro EDM

2014 ◽  
Vol 941-944 ◽  
pp. 2116-2120 ◽  
Author(s):  
Qing Yu Liu ◽  
Qin He Zhang ◽  
Jian Hua Zhang ◽  
Min Zhang
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Micro Edm ◽  
Test Results ◽  
Machining Performance ◽  
Grain Sizes ◽  
Stainless Steel 304 ◽  
Micro Holes ◽  
The Difference ◽  
Micro Features

Micro EDM is used to machine micro features which are of the same size order as material microstructure of workpiece. Due to the difference of the thermal properties between the crystal grain and grain boundary, the machining performance of micro EDM varies with the crystal grain sizes of workpiece. This paper investigated on the influence of grain size and grain boundary on the machining performance of micro EDM. By drilling micro holes on two pieces of stainless steel 304 (SUS 304) which are different in grain sizes, test results revealed that the characteristics of micro EDM is influenced by grain sizes of workpiece materials significantly.

Theoretical Calculation for the Young's Modulus of Poly-Si and a-Si Films

1992 ◽  
Vol 276 ◽  
Author(s):  
Shuwen Guo ◽  
Daowen Zou ◽  
Weiyuan Wang
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Theoretical Calculation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Boundary Effects ◽  
Wide Range ◽  
Si Films

ABSTRACTA newly theoretical calculation for the Young's modulus Ey of poly-Si and a-Si thin films based on the combination of grain and grain boundary effects as well as the dependance of crystalline orientations is presented. The calculated results are in agreement with the experimental results in a wide range of grain size and hydrogen concentrations published in the literatures. The reason for aberration among experimental data of poly-Si and a-Si films caused by different hydrogen concentrations, texture and grain size has been discussed. The results offer a better understanding of. the effects of film structures on elastic properties of poly-Si and a-Si films.

scholarly journals Morphology and Electron Emission Properties of Nanocrystalline CVD Diamond Thin Films

1997 ◽  
Vol 495 ◽  
Author(s):  
Alan R. Krauss ◽  
Dieter M. Gruen ◽  
Daniel Zhou ◽  
Thomas G. Mccauley ◽  
Lu Chang Qin ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Hydrogen Concentration ◽  
Electron Emission ◽  
Microwave Plasma ◽  
Initial Growth ◽  
Average Grain Size ◽  
Diamond Thin Films

ABSTRACTNanocrystalline diamond thin films have been produced by microwave plasma-enhanced chemical vapor deposition (MPECVD) using C60/Ar/H2 or CH4/Ar/H2 plasmas. Films grown with H2 concentration ≤ 20% are nanocrystalline, with atomically abrupt grain boundaries and without observable graphitic or amorphous carbon phases. The growth and morphology of these films are controlled via a high nucleation rate resulting from low hydrogen concentration in the plasma. Initial growth is in the form of diamond, which is the thermodynamic equilibrium phase for grains < 5 nm in diameter. Once formed, the diamond phase persists for grains up to at least 15–20 nm in diameter. The renucleation rate in the near-absence of atomic hydrogen is very high (∼1010 cm2sec−1), limiting the average grain size to a nearly constant value as the film thickness increases, although the average grain size increases as hydrogen is added to the plasma. For hydrogen concentrations less than ∼20%, the growth species is believed to be the carbon dimer, C2, rather than the CH3* growth species associated with diamond film growth at higher hydrogen concentrations. For very thin films grown from the C60 precursor, the threshold field (2 to ∼60 volts/micron) for cold cathode electron emission depends on the electrical conductivity and on the surface topography, which in turn depends on the hydrogen concentration in the plasma. A model of electron emission, based on quantum well effects at the grain boundaries is presented. This model predicts promotion of the electrons at the grain boundary to the conduction band of diamond for a grain boundary width ∼3–4 Å, a value within the range observed by TEM.

FEM-MD Coupling Simulation for Strength and Fracture Analyses Near Grain Boundary Zone of Structural Steels

2006 ◽  
Author(s):  
Masahito Mochizuki ◽  
Ryota Higuchi ◽  
Jinya Katsuyama ◽  
Masao Toyoda
Keyword(s):  
Stress Distribution ◽  
Grain Boundary ◽  
Grain Orientation ◽  
Grain Shape ◽  
Material Design ◽  
Strength Properties ◽  
Structural Steels ◽  
Coupling Method ◽  
Stress Distributions ◽  
The Difference

FEM-MD coupling method is proposed for the evaluation of the strength properties of structural steels. It is important to investigate the stress distribution by considering the microscopic heterogeneity and deformation near the grain boundary for clarification of the mechanism of fracture and the material design. FEM-MD coupling method is used to estimate the stress distribution. Especially, the influence of microstructure of steel on strength properties is investigated by estimating the difference of stress distributions caused by different distributions of the grain shape, such as grain diameter, aspect ratio and grain orientation.

scholarly journals Finite Element Analysis of Grain Size Effects on Curvature in Micro-Extrusion

2020 ◽  
Vol 10 (14) ◽  
pp. 4767 ◽  
Author(s):  
Pavaret Preedawiphat ◽  
Numpon Mahayotsanun ◽  
Sedthawatt Sucharitpwatskul ◽  
Tatsuya Funazuka ◽  
Norio Takatsuji ◽  
...  
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Grain Boundary ◽  
Grain Orientation ◽  
Value Added ◽  
Dominant Factor ◽  
Driving Mechanism ◽  
Curvature Index ◽  
Micro Parts ◽  
Single Grain

The precision and accuracy of the final geometry in micro-parts is crucial, particularly for high-value-added metallic products. Micro-extrusion is one of the most promising processes for delivering high-precision micro-parts. The curving tendency observed in micro-extrusion parts is a major concern, significantly affecting the final part geometry. The purpose of this paper was to investigate the driving mechanism behind the curvature in micro-extrusion at room temperature. A finite element (FE) simulation was carried out to observe the influential primary factors: (1) grain size, (2) grain boundary, (3) grain orientation, and (4) bearing length of a 6063 aluminum alloy. The Extrusion Curvature Index (ECI) was also established to indicate the level of curvature in micro-extruded parts. The results showed that the grain boundary at the high strain and die opening area was the dominant factor for single-grain conditions. The interactive effects of the grain boundary and grain orientation also affected the curvature under single-grain conditions. If the number of grains across the specimen increased up to 2.7 (poly-grains), the curvature effect was dramatically reduced (the pins were straightened). For all conditions, the curvature in micro-extrusion could be eliminated by extending the bearing length up to the exit diameter length.

Mechanisms for Microstructure Evolution in Electroplated Copper Thin Films

1999 ◽  
Vol 562 ◽  
Author(s):  
J. M. E. Harper ◽  
C. Cabral ◽  
P. C. Andricacos ◽  
L. Gignac ◽  
I. C. Noyan ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Electron Scattering ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Tensile Direction ◽  
Transient Period ◽  
Grain Boundary Pinning ◽  
Electroplated Copper

ABSTRACTWe present a model which accounts for the dramatic evolution in the microstructure of electroplated copper thin films near room temperature. Microstructure evolution occurs during a transient period of hours following deposition, and includes an increase in grain size, changes in preferred crystallographic texture, and decreases in resistivity, hardness and compressive stress. As the grain size increases from the as-deposited value of 0.05–0.1 μm up to several μm, the decreasing grain boundary contribution to electron scattering lowers the resistivity by tens of percent to near-bulk values. Concurrently, as the volume of grain boundaries decreases, the stress is shown to change in the tensile direction by tens of MPa. The as-deposited grain size is also shown to be consistent with grain boundary pinning.

Effect of Processing Conditions on Electrical and Magnetic Properties of Pb(Zr, Ti)O3 CoFe2O4 Multilayers Thin Films

2007 ◽  
Vol 1000 ◽  
Author(s):  
Nora Patricia Ortega ◽  
P. Bhattacharya ◽  
Ram S Katiyar ◽  
S B Majumder ◽  
I Takeuchi ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Grain Boundary ◽  
Layer Structure ◽  
Electrical Response ◽  
Hysteresis Loops ◽  
Multilayer Films ◽  
Electrical And Magnetic Properties ◽  
Modulus Spectroscopy ◽  
The Difference

The multilayers of ferroelectric (FE) Pb(Zr, Ti)O3 (PZT) and ferromagnetic (FM) CoFe2O4 (CFO) thin films with 3, 5, and 9 layers having configurations PZT/CFO (PC) and CFO/PZT (CP) were fabricated by pulsed laser deposition technique. We have investigated the effect of inter-diffusion at the interface of multilayers (MLs) and reversing the order of FE and FM layers in the multilayers configuration on the electrical/magnetic properties. The TEM of the films showed that the layer structure was not maintained and the inter-diffusion of the CFO into PZT and vice verse were observed at the interface of MLs. Both the PC and CP configurations of multilayer films exhibited pseudo FE hysteresis loop and proper FM hysteresis loops at room temperature. Reversing the multilayer configuration from CP to PC resulted in increasing the pseudo remanent polarization, however this behavior was not observed in magnetic properties. The frequency and temperature dependences of the impedance and modulus spectroscopy of the multilayer PC and CP films were studied in the ranges of 102 to 106 Hz and 200 to 650 K respectively. The electrical response of all multilayer films investigated could be resolved into two contributions. We attributed these to the grain and grain boundary effects in impedance and modulus formalism. We found that the difference between the grain and grain boundary capacitive effect decreased due to increase of the number of layers.

Sign in / Sign up

Export Citation Format

Share Document