scholarly journals Atomic Layer Deposition of Insulating AlF3/Polyimide Nanolaminate Films

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 355
Author(s):  
Xinzhi Li ◽  
Marko Vehkamäki ◽  
Mikko Heikkilä ◽  
Miika Mattinen ◽  
Matti Putkonen ◽  
...  

This article describes the deposition of AlF3/polyimide nanolaminate film by inorganic-organic atomic layer deposition (ALD) at 170 °C. AlCl3 and TiF4 were used as precursors for AlF3. Polyimide layers were deposited from PMDA (pyromellitic dianhydride, 1,2,3,5-benzenetetracarboxylic anhydride) and DAH (1,6-diaminohexane). With field-emission scanning electron microscopy (FESEM) and X-ray reflection (XRR) analysis, it was found that the topmost layer (nominally 10 nm in thickness) of the nanolaminate film (100 nm total thickness) changed when exposed to the atmosphere. After all, the effect on roughness was minimal. The length of a delay time between the AlF3 and polyimide depositions was found to affect the sharpness of the nanolaminate structure. Electrical properties of AlF3/polyimide nanolaminate films were measured, indicating an increase in dielectric constant compared to single AlF3 and a decrease in leakage current compared to polyimide films, respectively.

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2345
Author(s):  
Maxim Maximov ◽  
Denis Nazarov ◽  
Aleksander Rumyantsev ◽  
Yury Koshtyal ◽  
Ilya Ezhov ◽  
...  

Lithium nickelate (LiNiO2) and materials based on it are attractive positive electrode materials for lithium-ion batteries, owing to their large capacity. In this paper, the results of atomic layer deposition (ALD) of lithium–nickel–silicon oxide thin films using lithium hexamethyldisilazide (LiHMDS) and bis(cyclopentadienyl) nickel (II) (NiCp2) as precursors and remote oxygen plasma as a counter-reagent are reported. Two approaches were studied: ALD using supercycles and ALD of the multilayered structure of lithium oxide, lithium nickel oxide, and nickel oxides followed by annealing. The prepared films were studied by scanning electron microscopy, spectral ellipsometry, X-ray diffraction, X-ray reflectivity, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction. The pulse ratio of LiHMDS/Ni(Cp)2 precursors in one supercycle ranged from 1/1 to 1/10. Silicon was observed in the deposited films, and after annealing, crystalline Li2SiO3 and Li2Si2O5 were formed at 800 °C. Annealing of the multilayered sample caused the partial formation of LiNiO2. The obtained cathode materials possessed electrochemical activity comparable with the results for other thin-film cathodes.


2012 ◽  
Vol 1408 ◽  
Author(s):  
Cagla Ozgit ◽  
Fatma Kayaci ◽  
Inci Donmez ◽  
Engin Cagatay ◽  
Tamer Uyar ◽  
...  

ABSTRACTAl2O3 and AlN nanotubes were fabricated by depositing conformal thin films via atomic layer deposition (ALD) on electrospun nylon 66 (PA66) nanofiber templates. Depositions were carried out at 200°C, using trimethylaluminum (TMAl), water (H2O), and ammonia (NH3) as the aluminum, oxygen, and nitrogen precursors, respectively. Deposition rates of Al2O3 and AlN at this temperature were ∼1.05 and 0.86 Å/cycle. After the depositions, Al2O3- and AlN-coated nanofibers were calcinated at 500°C for 2 h in order to remove organic components. Nanotubes were characterized by using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). AlN nanotubes were polycrystalline as determined by high resolution TEM (HR-TEM) and selected area electron diffraction (SAED). TEM images of all the samples reported in this study indicated uniform wall thicknesses.


2015 ◽  
Vol 10 (1) ◽  
pp. 49-58
Author(s):  
Danilo R. Huanca ◽  
V. Christiano ◽  
C. Adelmann ◽  
Patrick Verdonck ◽  
Sebastião G. Dos Santos Filho

Hafnium aluminates films with 50 mol% of Hf were deposited onto Si(100) using atomic layer deposition. The films were annealed by RTP at 1000 oC for 60 s in pure N2 or N2+5%O2 and by LASER at 1200oC for 1ms in pure N2. Then, they were characterized by X-ray spectroscopies, ellipsometry, Rutherford backscattering and scanning electron microscopy. For thin films annealed by RTP in N2, phase separation takes place, promoting the formation of HfO2 and Al2.4 O3.6 crystalline phases. In contrast, the films annealed by LASER remain predominantly amorphous with crystalline facets of Al2.4O3.6. Also, non-homogeneous distribution of the chemical elements within the dielectrics gave rise to the formation of several regions which can be viewed as sub-layers, each of them with arbitrary electron density and thickness. As a result, Kratky curves pointed out to the coexistence of different features described by different gyration radius yielding GISAXS scattering profiles with polydispersive characteristics. Finally, the samples annealed by RTP were interpreted as agglomerates of spheroids with different sizes (1.1-2.2 nm) and with different crystalline phases whereas the samples annealed by LASER were interpreted as larger spheroids of crystalline Al2.4O3.6 (1.7-2.7nm) embedded in a matrix predominantly amorphous.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


Author(s):  
Yun Lu ◽  
David C. Joy

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


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