Aging Effects on the Durability of Tantalum Nitride Films

1997 ◽  
Vol 505 ◽  
Author(s):  
N. R. Moody ◽  
D. Medlin ◽  
D. Boehme ◽  
D. Norwood

ABSTRACTIn this study, nanoindentation and nanoscratch testing were used to determine the effects of annealing and long term aging on the properties and fracture resistance of thin tantalum nitride resistor films on aluminum nitride substrates. These films were sputter-deposited to a thickness of 440 nm. Some films were left in the as-deposited condition while others were annealed or annealed and then aged. X-ray diffraction revealed that sputter deposition created high compressive residual stresses in the as-deposited films which were partially relieved by annealing. Subsequent aging of the annealed films had no effect on residual stress levels. Nanoindentation showed that mechanical properties were unchanged after annealing and after annealing and aging. However, nanoscratch testing showed that annealing markedly reduced the susceptibility to catastrophic failure with no further changes discernible after aging.

1987 ◽  
Vol 103 ◽  
Author(s):  
Bruce M. Clemens ◽  
D. L. Williamson

ABSTRACTIron zirconium multilayer films were prepared by electron beam evaporation and by sputter deposition. Layer thicknesses were varied from 50 monolayers of each constituent down to 2 monolayers. Conversion electron Mössbauer spectroscopy, x-ray diffraction, and Auger spectroscopy have been used to characterize multilayers in the as-deposited and annealed state. Amorphous phase formation occurs during thermal anneals, and samples with layer thicknesses of 5 monolayers or less of each constituent are amorphous as deposited. Amorphous interfaces are observed in all samples, with this interface region being larger in the electron beam evaporated samples than in the sputter deposited samples.


2007 ◽  
Vol 40 (4) ◽  
pp. 796-798 ◽  
Author(s):  
Bingyun Ao ◽  
Xiaolin Wang ◽  
Yongjun Wei ◽  
Yanzhi Zhang

In order to help resolve unknowns regarding aging effects of uranium during long-term storage of tritium, a number of experiments have been carried out by several researchers. However, almost no literature is available on the structural change of uranium tritide, mainly because its high toxicity and air-sensitivity render appropriate experiments very difficult. In this paper, a simple hermetic sample holder that fits the Philips X'Pert Pro X-ray diffractometer is described. It may be used to study the aging effects of uranium tritide during storage. The sample holder mainly consists of an aluminium container for sample storage and a Mylar window for X-ray measurements. This sample holder can also be used with other air-sensitive, radioactive and toxic materials. In this paper, the first results obtained from X-ray diffraction analysis of uranium hydride are presented.


2005 ◽  
Vol 890 ◽  
Author(s):  
James Krzanowski ◽  
Dyumani Nunna

ABSTRACTThe tribological properties of sputter-deposited MoS2 and MoS2-Ti films were investigated in this study. The deposited films were characterized using microprobe analysis for composition and x-ray diffraction (XRD) for structure. The frictional properties of the films were examined using a pin-on-disk (POD) with counterfaces of 440C steel, aluminum, tungsten carbide and alumina. The tests were run under low (25%), medium (50%) and high (70%) humidity levels. MoS2 films without Ti were first examined under cyclic humidity conditions between 25 and 50% R/H. The results showed that for steel, WC and alumina counterfaces, the effect of the higher humidity was to increase the friction, but lower friction could be recovered when the humidity was reduced back to 25%. For films containing Ti, the best results were obtained at a concentration of 20 at. % Ti. These films performed well for steel and WC counterfaces, but poorly against aluminum. The effect of deposition temperature (up to 450oC) was examined for MoS2 and MoS2-5% Ti films. Higher temperatures yielded more crystalline films, but the addition of Ti partially countered this effect. The POD test showed that at medium humidity levels the friction decreased with temperature, but increased slightly when tested under low humidity. In all cases, the 5% Ti-containing films had a fiction coefficient of about 0.1 below that for films without Ti.


1983 ◽  
Vol 25 ◽  
Author(s):  
K.L. Kavanagh ◽  
S.H. Chen ◽  
C.J. Palmstrom ◽  
C.B. Carter

ABSTRACTElectron-beam and sputter-deposited Ta silicides on GaAs were annealed in an As2 overpressure ambient to temperatures as high as 920°C for 20mim. The films were then characterized with RBS, cross-sectional TEM and both electron and x-ray diffraction. The morphology of sputtered TaSi2/GaAs interfaces did not change, however, some interaction was detected at electron-beam deposited GaAs/silicide interfaces. Arsenic in-diffusion was detected at temperatures above 800°C and it was found to be dependent on the stoichiometry of the films. Arsenic diffusion into Si-rich electron-beam and sputter deposited films was low, whereas significantly more As diffused into the Ta-rich silicide. Some indium (3×l015atoms/cm2), from the InAs used as the source of As2overpressure, was observed to accumulate at all GaAs/silicide interfaces at temperatures above 800°C.


1996 ◽  
Vol 458 ◽  
Author(s):  
N. R. Moody ◽  
R. Q. Hwang ◽  
J. E. Angelo ◽  
S. Venkataraman ◽  
W. W. Gerberich

ABSTRACTIn this study, continuous microscratch testing was used to determine the effects of compressive residual stresses on the fracture of thin tantalum nitride films. The films were sputter deposited at room temperature onto single crystal sapphire substrates to a thickness of 600 nm. Some films were left in the as-deposited condition while the remaining films were vacuum annealed at 300°C. The only discernible change in structure was a surface rearrangement of atoms into parallel arrays of striations on the vacuum annealed samples revealing a high compressive residual stress in the films. These stresses had a strong effect on fracture as shown by the as-deposited films which buckled readily during scratch tests forming uniform-width and circular blisters while the vacuum annealed films exhibited a much lower susceptibility to fracture. Application of mechanics-based models for film buckling defined the levels of compressive residual stress and their effect on interfacial fracture.


Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.


2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.


2013 ◽  
Vol 1494 ◽  
pp. 77-82
Author(s):  
T. N. Oder ◽  
A. Smith ◽  
M. Freeman ◽  
M. McMaster ◽  
B. Cai ◽  
...  

ABSTRACTThin films of ZnO co-doped with lithium and phosphorus were deposited on sapphire substrates by RF magnetron sputtering. The films were sequentially deposited from ultra pure ZnO and Li3PO4 solid targets. Post deposition annealing was carried using a rapid thermal processor in O2 and N2 at temperatures ranging from 500 °C to 1000 °C for 3 min. Analyses performed using low temperature photoluminescence spectroscopy measurements reveal luminescence peaks at 3.359, 3.306, 3.245 eV for the co-doped samples. The x-ray diffraction 2θ-scans for all the films showed a single peak at about 34.4° with full width at half maximum of about 0.17°. Hall Effect measurements revealed conductivities that change from p-type to n-type over time.


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