scholarly journals Nanoindentation of Chromium Oxide Possessing Superior Hardness among Atomic-Layer-Deposited Oxides

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Taivo Jõgiaas ◽  
Aivar Tarre ◽  
Hugo Mändar ◽  
Jekaterina Kozlova ◽  
Aile Tamm
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Organic Chemical ◽  
X Ray ◽  
Layer Deposition ◽  
Ammonium Dichromate ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Deposition Substrate

Chromium (III) oxide is a technologically interesting material with attractive chemical, catalytic, magnetic and mechanical properties. It can be produced by different chemical and physical methods, for instance, by metal–organic chemical vapor deposition, thermal decomposition of chromium nitrate Cr(NO3)3 or ammonium dichromate (NH4)2Cr2O7, magnetron sputtering and atomic layer deposition. The latter method was used in the current work to deposit Cr2O3 thin films with thicknesses from 28 to 400 nm at deposition temperatures from 330 to 465 °C. The phase composition, crystallite size, hardness and modulus of elasticity were measured. The deposited Cr2O3 thin films had different structures from X-ray amorphous to crystalline α-Cr2O3 (eskolaite) structures. The averaged hardness of the films on SiO2 glass substrate varied from 12 to 22 GPa and the moduli were in the range of 76–180 GPa, as determined by nanoindentation. Lower values included some influence from a softer deposition substrate. The results indicate that Cr2O3 could be a promising material as a mechanically protective thin film applicable, for instance, in micro-electromechanical devices.

scholarly journals Aluminum Nitride Transition Layer for Power Electronics Applications Grown by Plasma-Enhanced Atomic Layer Deposition

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 406 ◽  
Author(s):  
Heli Seppänen ◽  
Iurii Kim ◽  
Jarkko Etula ◽  
Evgeniy Ubyivovk ◽  
Alexei Bouravleuv ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Aluminum Nitride ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Organic Chemical ◽  
Layer Deposition ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Aluminum nitride (AlN) films have been grown using novel technological approaches based on plasma-enhanced atomic layer deposition (PEALD) and in situ atomic layer annealing (ALA). The growth of AlN layers was carried out on Si<100> and Si<111> substrates at low growth temperature. The investigation of crystalline quality of samples demonstrated that PEALD grown layers were polycrystalline, but ALA treatment improved their crystallinity. A thick polycrystalline AlN layer was successfully regrown by metal-organic chemical vapor deposition (MOCVD) on an AlN PEALD template. It opens up the new possibilities for the formation of nucleation layers with improved quality for subsequent growth of semiconductor nitride compounds.

Deposition of AlN on WS2 (0001) Substrate by Atomic Layer Growth Process

1996 ◽  
Vol 449 ◽  
Author(s):  
J-W. Chung ◽  
F.S. Ohuchi
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Layer Growth ◽  
Organic Chemical ◽  
Close Proximity ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Potential Substrate ◽  
Deposition Conditions

ABSTRACTClose proximity of the lattice constant for tungsten disulfide and aluminum nitride has lead to an investigation to use WS2 as a potential substrate for the growth of AIN. Metal organic chemical vapor deposition(MOCVD) has been develop to fabricated WS2 thin films on Si(001) with their basal planes parallel to the substrate. AIN thin film was subsequently grown by atomic layer growth (ALG) process using dimethylamine-alane (DMEAA) and ammonia (NH3). Deposition conditions for WS2 thin films by MOCVD, and AIN growth on WS2 by ALG are described.

Metal-Organic Chemical Vapor Deposition of Epitaxial Tl2Ba2Ca2Cu3O10−x Thin Films

1993 ◽  
Vol 335 ◽  
Author(s):  
Bruce J. Hinds ◽  
Jon L. Schindler ◽  
Bin Han ◽  
Deborah A. Neumayer ◽  
Donald C. Degroot ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Superconducting Thin Films ◽  
X Ray ◽  
Partial Pressures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractSuperconducting thin films of Tl2Ba2Ca2Cu3O10−x (TL-2223) have been grown on single crystal (110) LaAlO3 using a two-step process. Ba2Ca2Cu3Ox precursor films are deposited via metal-organic chemical vapor deposition (MOCVD) in a horizontal hot walled reactor. The second generation precursors Ba(hfa)2•tet, Ca(hfa)2•tet, and Cu(hfa)2 (hfa = hexafluoroacetylacetonate, tet = tetraglyme) were used as volatile metal sources due to their superior volatility and stability. Tl was introduced into the film via a high temperature post anneal in the presence of a Tl2O3:BaO:CaO:CuO pellet (1:2:2:3 ratio). Low O2 partial pressures were used to reduce the temperature in which the TI-2223 phase forms and to improve the surface morphology associated with a liquid phase intermediate. Films are highly oriented with the c-axis perpendicular to the substrate and a-b axis epitaxy is seen from x-ray φ- scans. The best films have a resistively measured Tc of 115K and a magnetically derived Jc of 6×105 A/cm2 (77K, 0 T). Preliminary surface resistance measurements, using parallel plate techniques, give Rs = 0.35 mΩ at 5K (ω = 10 GHz).

Grain morphology and cation composition heterogeneity of Pb(ZrxTi1–x)O3 thin films deposited by metal-organic chemical vapor deposition

1998 ◽  
Vol 13 (6) ◽  
pp. 1614-1625 ◽  
Author(s):  
I-Fei Tsu ◽  
G-R. Bai ◽  
C. M. Foster ◽  
K. L. Merkle ◽  
K. C. Liu
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Grain Morphology ◽  
Organic Chemical ◽  
Cation Composition ◽  
X Ray ◽  
Pzt Films ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

The preferred orientation, grain morphology, and composition heterogeneity of the polycrystalline Pb(ZrxTi1–x)O3 (PZT) thin films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and x-ray energy dispersive spectroscopy (EDS). PZT thin films with nominal x = 0.5 were grown by metal-organic chemical vapor deposition (MOCVD) on (110)- and (101)-textured RuO2 bottom electrodes at temperatures ≤525 °C. Columnar grain microstructure with strongly faceted surface morphology was observed in both films. The grain morphology and surface roughness of the PZT films were observed to depend on those of the underlying RuO2 layers. TEM-EDS analysis shows notable cation composition heterogeneity in length scales of 0.2–2 μm. Pronounced Pb composition deficiency and heterogeneity were also observed in PZT/(110)RuO2 in length scales above 40 μm. The grain morphology and cation heterogeneity of the PZT films are discussed on the basis of diffusion-limited columnar growth mechanism.

Epitaxial and Conductive RuO2 Thin Films Grown on MgO and LaAlO3 by MOCVD

1998 ◽  
Vol 541 ◽  
Author(s):  
P. Lu ◽  
S. He ◽  
F. X. Li ◽  
Q. X. Jia
Keyword(s):  
Thin Films ◽  
Orientation Relationship ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractConductive RuO2 thin films have been grown epitaxially on (100) MgO and (100) LaAlO3 substrates by metal-organic chemical vapor deposition(MOCVD) at different temperatures. The microstructural properties of the RuO2 films have been studied using x-ray diffraction and scanning electron microscopy. Different growth and microstructure properties were observed for the films deposited on the two substrates. The films on MgO are epitaxial at deposition temperatures as low as 350°C, and consist of two variants with an orientation relationship given by (110) RuO2 /(100) MgO and [001] RuO2//[011]MgO. The films on LaAlO3, on the other hand, are epitaxial only at deposition temperatures of 600°C and above, and contain four variants with an orientation relationship given by (200)RuO2//(100)LaAlO3 and [011] RuO2//[011] LaAlO3. The observed microstructures of epitaxially grown films can be explained based on geometric considerations for the films and substrates.

Deposition of Superconducting Tl-Ba-Ca-Cu-O Phases on Metal Foils by Metal-Organic Chemical Vapor Deposition

1992 ◽  
Vol 275 ◽  
Author(s):  
D. L. Schulzi ◽  
B. Hano ◽  
D. Neumayer ◽  
B. J. Hinds ◽  
T. J. Markst ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Foils ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTThe synthesis of superconducting Tl-Ba-Ca-Cu-O thin films on metal foils (Au and Ag) by metal-organic chemical vapor deposition (MOCVD) has been investigated. Ba-Ca-Cu-O-(F) films are first prepared via MOCVD using fluorinated “second generation” metal-organic precursors. After an intermediate anneal with water vapor-saturated oxygen to promote removal of F, Tl is introduced by annealing in the presence of a mixture of oxides (Tl2O3, BaO, CaO, CuO) of a specific composition. Characterization of the thin films by scanning electron microscopy, EDX, x-ray diffraction, and variable temperature magnetization measurements has been carried out. High temperature superconductor (HTS) films of Tl2Ba2Ca1Cu2O8−x on Au foil exhibit a magnetically derived Tc = 80K and a high degree of texturing with the crystallite c-axes oriented perpendicular to the substrate surface as evidenced by enhanced (000 x-ray diffraction reflections. Thin film coverage on Ag foil becomes non-contiguous during the (Tl2O3, BaO, CaO, CuO) mixture anneal.

Sign in / Sign up

Export Citation Format

Share Document