Polycrystalline Grain Structure of Sputtered Aluminum Nitride Films

1994 ◽  
Vol 343 ◽  
Author(s):  
Asher T Matsuda ◽  
H. Ming Liaw ◽  
Wayne A Cronin ◽  
Harland G Tompkins ◽  
Peter L Fejes ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Morphology ◽  
Aluminum Nitride ◽  
Columnar Structure ◽  
Preferred Orientation ◽  
Grain Structure ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Acoustic Wave Devices

ABSTRACTReactively-sputtered, polycrystalline thin film aluminum nitride (AlN) is an attractive material for use in acoustic wave devices, for which it requires a strong preferred orientation, similar to that found in epitaxial films. This investigation evaluated the grain structure including preferred orientation, grain size, and surface morphology of sputtered A1N films. The characterization techniques utilized included x-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The results revealed two types of grain structure: 1) a single-grain columnar structure that is perfectly oriented in the [001] direction throughout the entire film thickness and 2) a multiple-grain columnar structure that possesses a strong [001] orientation at the bottom of the film and a tilted [001] combined with other orientations at the top of the film. Strong correlations between orientation and surface morphology, oxygen content, and grain size were observed, namely higher degrees of c-axis orientation correlated with lower mean surface roughness values, reduced oxygen concentration, and narrower grains.

scholarly journals Surface Morphology Investigations of Nanocrystalline R2Fe14B (R = Y, Nd, Gd, Er) by Atomic Force Microscopy

2022 ◽  
Author(s):  
I. Pelevin
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Rare Earth ◽  
Surface Morphology ◽  
Size Dependence ◽  
Atomic Weight ◽  
Grain Structure ◽  
Linear Character ◽  
Force Microscopy ◽  
Atomic Force

Abstract. The study was aimed at microstructure investigations of melt-spun rare-earth intermetallic compounds using atomic force microscopy. Surface morphology of R2Fe14B (R = Y, Nd, Gd, Er) was studied with nanometric resolution. Grain structure features were discovered depending on the rare-earth element composition and quenching regime. Grain size dependence on rare earth elements' composition decreased with the metal's serial number and atomic weight. Wherein structural size dependence on quenching wheel speed had non-linear character: increase the speed from 20 to 30 m/s led to 3 times decrease of the grain size and significant surface roughness reduction.

scholarly journals The Domain and Microstructure of Resin-Bonded Magnets

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2849
Author(s):  
Marcin Jan Dośpiał
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Size Distribution ◽  
Domain Structure ◽  
Grain Size Distribution ◽  
Exchange Interactions ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Scanning Electron

This paper presents domain and structure studies of bonded magnets made from nanocrystalline Nd-(Fe, Co)-B powder. The structure studies were investigated using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Mössbauer spectroscopy and X-ray diffractometry. On the basis of performed qualitative and quantitative phase composition studies, it was found that investigated alloy was mainly composed of Nd2(Fe-Co)14B hard magnetic phase (98 vol%) and a small amount of Nd1.1Fe4B4 paramagnetic phase (2 vol%). The best fit of grain size distribution was achieved for the lognormal function. The mean grain size determined from transmission electron microscopy (TEM) images on the basis of grain size distribution and diffraction pattern using the Bragg equation was about ≈130 nm. HRTEM images showed that over-stoichiometric Nd was mainly distributed on the grain boundaries as a thin amorphous border of 2 nm in width. The domain structure was investigated using a scanning electron microscope and metallographic light microscope, respectively, by Bitter and Kerr methods, and by magnetic force microscopy. Domain structure studies revealed that the observed domain structure had a labyrinth shape, which is typically observed in magnets, where strong exchange interactions between grains are present. The analysis of the domain structure in different states of magnetization revealed the dynamics of the reversal magnetization process.

scholarly journals Characterization and Alumina Leachability of 12CaO·7Al2O3with Different Holding Times

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hui-lan Sun ◽  
Bo Wang ◽  
Jian-xin Zhang ◽  
Shu-feng Zong
Keyword(s):  
Grain Size ◽  
Surface Morphology ◽  
Lattice Constant ◽  
Preferred Orientation ◽  
Holding Time ◽  
Synthesis Time ◽  
Rate Of Increase ◽  
Average Grain Size ◽  
Long Time ◽  
Scherrer Formula

The effect of synthesis time on phase compositions, lattice constant, average grain size, preferred orientation, and surface morphology of 12CaO·7Al2O3synthesized at 1500°C was analyzed by XRD and SEM. The results indicate that the main phase of samples synthesized is 12CaO·7Al2O3when holding time is over 30 min. The lattice constant increases and the preferred orientation decreases as synthesis time prolongs. The average grain size of samples is about 59 nm calculated by Scherrer formula, and it does not change with synthesis time. The synthesis time affects the micromorphology of samples greatly. There are more and bigger holes in samples synthesized for long time. The aspects mentioned above cause the alumina leaching ratio of 12CaO·7Al2O3to increase with the prolonging of synthesis time, but the rate of increase drops.

Grain Size and Strength of the Ni3Al Intermetallic Compound Synthesized under Pressure

2021 ◽  
Vol 313 ◽  
pp. 41-49
Author(s):  
Vladimir Ovcharenko ◽  
Alexander Kozulin ◽  
K.O. Akimov
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Intermetallic Compound ◽  
Stoichiometric Composition ◽  
Strength Properties ◽  
Grain Structure ◽  
Significant Shift ◽  
Anomalous Temperature ◽  
High Temperature Synthesis ◽  
Transmission Electron

This paper presents the results of the investigation of the grain structure formation in the intermetallic compound Ni3Al under conditions of its high-temperature synthesis under pressure in a powder mixture of nickel and aluminum of stoichiometric composition and the effect of grain size on the strength properties of the synthesized intermetallic compound. The grain structure was investigated by optical metallography, transmission electron microscopy, and EBSD analysis; the ultimate tensile strength of the intermetallic compound was investigated under the tension of the samples in the temperature range from 20 to 1000 °C. It was found that with a decrease in the grain size, not only does the tensile strength of the intermetallic compound multiply increases but also on the anomalous temperature dependence of the intermetallic compound strength there is a significant shift in the maximum strength value to the region of higher temperatures.

Microstructural features and mechanical properties of 18 MeV He+ ions irradiated pure Zr

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650395
Author(s):  
Mohsin Rafique ◽  
San Chae ◽  
Yong-Soo Kim
Keyword(s):  
Grain Size ◽  
Irradiation Dose ◽  
Dose Range ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Pure Zirconium ◽  
Higher Doses

Samples of pure zirconium (Zr) were irradiated by 18 MeV helium (He[Formula: see text]) ions in the dose range 0.00162–0.0324 dpa at 373 K by using Cyclotron accelerator. The atomic force microscopy (AFM) results indicated an increase in average surface roughness of Zr by increasing the irradiation dose. The AFM images revealed nucleation and growth of nano- and micro-size hillocks at lower doses (0.00162–0.00324 dpa), whereas formation of a volcano-like cavities and craters was observed within these hillocks by increasing the radiation dose from 0.00324 to 0.0324 dpa. The high-resolution X-ray diffraction (XRD) results showed a variation in the intensities and positions of the diffraction peaks after the irradiation. The transmission electron microscopy (TEM) results reported a significant decrease in the grain size after the He[Formula: see text] irradiation. The values of grain size, calculated using the TEM, were found to be in good agreement with the crystallite size calculated using the XRD analysis. The yield stress (YS) was increased by increasing the irradiation dose up to 0.0162 dpa, however, the YS exhibited a decreasing trend with a further increase of the dose. The changes in YS were elucidated by grain size reduction and localized heating at higher doses.

Surface Morphology Investigation of Au and Pt Electroless Contact on ZnCdTe Crystal by Atomic Force Microscopy

1995 ◽  
Vol 378 ◽  
Author(s):  
Zhiyu Hu ◽  
Zhihua Hu ◽  
K. T. Chen ◽  
M. A. George ◽  
A. Burger ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Morphology ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Platinum Metal ◽  
Heat Treatments ◽  
Metal Contacts ◽  
Force Microscopy ◽  
Atomic Force

AbstractGold and platinum metal contacts have been deposited on the cleaved and etched surfaces of ZnCdTe single crystals by “electroless” method from AuCl3, PtCl2 and PtCl4 aqueous solutions with different concentrations and deposition times. Atomic Force Microscopy (AFM) has been employed to reveal the surface morphology of metal contacts and it was found that for AuCl3 and PtCl2 solutions, the surface morphology and grain size are similar, and uniformly distributed. The surface morphology on contact made from PtCl4 shows a larger grain size, higher roughness and non-uniformity. The effect of different heat treatments to the surface morphology will be discussed.

Surface Morphology of SiGe Epitaxial Layers Grown on Uniquely Oriented Si Substrates

2000 ◽  
Vol 648 ◽  
Author(s):  
Morgan E. Ware ◽  
Robert J. Nemanich
Keyword(s):  
Surface Morphology ◽  
Lattice Mismatch ◽  
Morphological Structure ◽  
Epitaxial Layers ◽  
Misfit Dislocations ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Relationship Of

AbstractThe 4% lattice mismatch between Si and Ge creates strain in epitaxial layers of SiGe alloys on Si, and this strain can manifest itself in the morphological structure of the surface of the epitaxial layer. This study explores the relationship of the evolution of the surface morphology of SiGe layers grown on a range of Si surface orientations. We have grown thin, strained and thick, relaxed layers of Si0.7Ge0.3 by solid source molecular beam epitaxy on substrates with surface normals rotated from [001] towards [111] by angles of θ = (0, 2, 4, 10, 22) degrees. The surface morphology was investigated by atomic force microscopy, which showed considerable ordering of surface features on relaxed samples. These features evolve from hut-like structures at 0 degrees to large mesa-like structures separated by pits and crevices at 22 degrees. The organization of these features is also shown to vary with the substrate orientation. Each surface has characteristic directions along which features are aligned, and these directions vary continuously with the angle of rotation of the substrate. Transmission electron microscopy confirmed that misfit dislocations had formed along those same directions. The state of relaxation of each layer is quantified by Raman spectroscopy in order to make a direct correlation between residual strain and surface morphology.

SURFACE MORPHOLOGY AND MICROSTRUCTURE OF DIRECT CURRENT SPUTTERING GROWTH OF BUFFER LAYERS FOR YBCO COATED CONDUCTOR

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3348-3351
Author(s):  
J. YANG ◽  
H. Z. LIU ◽  
H. ZHANG ◽  
F. QU ◽  
Q. ZHOU ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Buffer Layers ◽  
Coated Conductor ◽  
Force Microscopy ◽  
Ybco Coated Conductor ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Direct Current Sputtering ◽  
Niw Substrate

A composite buffer of CeO 2/ YSZ / Y 2 O 3 was investigated on the biaxially textured NiW long tape for YBCO coated conductor with magnetron sputtering technique. Every layer's surface morphology was observed by scanning electron microscopy. The seed layer Y 2 O 3 film was full coverage of the NiW substrate. The cap layer CeO 2 showed a smooth and crack-free surface and good crystallinity. The roughness of CeO 2 surface was measured by atom force microscopy. The transmission electron microscopy was used to analyze the cross-section of buffer layers and YBCO layer.

Surface Roughening and Composition Modulation of ZnSe-related II-VI epitaxial films

1996 ◽  
Vol 448 ◽  
Author(s):  
Shigetaka Tomiya ◽  
Hironori Tsukamoto ◽  
Satoshi Itoh ◽  
Kazushi Nakano ◽  
Etsuo Morita ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Surface Reconstruction ◽  
Epitaxial Films ◽  
Surface Roughening ◽  
Force Microscopy ◽  
Composition Modulation ◽  
Atomic Force ◽  
Transmission Electron ◽  
Rich Condition ◽  
Lattice Matched

AbstractWe have investigated ZnSSe and ZnMgSSe epitaxial layers lattice-matched to GaAs (001) substrates grown by molecular beam epitaxy using atomic force microscopy and transmission electron microscopy. Under II-rich conditions with c(2x2) surface reconstruction, surface morphology exhibited corrugation aligned in the [1ī0] direction and composition modulation was observed in the same [1ī0] direction. Under VI-rich condition with (2x1) surface reconstruction, the surface morphology becomes rounded grain-like and composition modulation was not observed. The formation of composition modulation is associated with the surface corrugated structures.

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