The Nature of Thermally Induced Stresses in Silicon and Their Relation to Observed X‐Ray Diffraction and Birefringence Phenomena

1968 ◽  
Vol 39 (8) ◽  
pp. 3813-3817 ◽  
Author(s):  
Gene J. Carron ◽  
L. K. Walford
2012 ◽  
Vol 733 ◽  
pp. 228-231 ◽  
Author(s):  
František Lukáč ◽  
Jakub Čížek ◽  
Marián Vlček ◽  
Ivan Procházka ◽  
Martin Vlach ◽  
...  

In the present work hydrothermally grown ZnO single crystals were electrochemically charged with hydrogen. The influence of hydrogen on ZnO microstructure was investigated by positron annihilation spectroscopy (PAS) combined with X-ray diffraction (XRD) using synchrotron radiation. Hydrogen concentration in the samples was determined by nuclear reaction analysis (NRA). It was found that a high concentration of hydrogen can be introduced into ZnO by electrochemical loading. At low concentrations, absorbed hydrogen causes elastic volume expansion of ZnO crystal. At higher concentration, hydrogen-induced stresses exceed the yield stress in ZnO and plastic deformation of the crystal takes place leading to formation of a defected subsurface layer in the crystals.


Clay Minerals ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 213-231 ◽  
Author(s):  
C. Henry ◽  
J.-Y. Boisson ◽  
A. Bouchet ◽  
A. Meunier

AbstractA mixed-layer illite-smectite, illite-rich calcareous mudstone intruded by a basaltic dyke at the Perthus Pass (southern Massif Central, France) allows us to study the transformation of clays subjected to a brief thermal gradient. X-ray diffraction, scanning electron microscopy, electron microprobe and atomic absorption spectroscopy analyses were performed on samples at variable distances from the mudstone-dyke contacts.A roughly similar evolution is seen on both sides of the dyke: quartz, calcite, kaolinite and illite disappear; Ca-silicates, albite and saponite-beidellite form, late meteoric halloysite crystallizes in open fractures.Chemical and mineralogical transformations are related to heat diffusion from the dyke. Theoretical calculations highlight the influence of the dyke orientation. The mineralogical reactions observed in rocks are similar to those observed in experimental conditions. The formation of new swelling phases with a high retention capacity linked to a short duration, large-temperature increase, should constitute a positive process for Repository Performance Assessment.


2008 ◽  
Vol 23 (2) ◽  
pp. 565-569 ◽  
Author(s):  
Runrun Duan ◽  
Michael S. Haluska ◽  
Robert F. Speyer

Compositions of xBiLaO3–(1 − x) PbTiO3 over the range 0 ≤ x ≤ 0.225 were calcined and sintered. The dielectric constant with temperature and differential scanning calorimetry measurements were in excellent agreement with respect to Curie-like tetragonal to cubic transformations starting at 495 °C for pure PbTiO3, shifting to lower temperatures with increasing x. For compositions of x ≥ 0.05, a second higher-temperature (∼600 °C) endotherm, and matching dielectric anomaly, were consistently observed, for which there were no structural changes indicated by hot-stage x-ray diffraction. This transformation was speculated to be based on a thermally induced desegregation of B-site cations.


1997 ◽  
Vol 505 ◽  
Author(s):  
R. C. Currie ◽  
R. Delhez ◽  
E. J. Mitiemeijer

ABSTRACTThe relaxation of thermally induced strain in 500 nm thick polycrystalline Ag layers electron-beam deposited onto Si wafers was traced during ageing at room temperature. The layers consisted predominantly of matrix crystallites with {111} planes parallel to the surface and twin crystallites with {51 l} planes parallel to the surface. The macrostrain in the plane of the layer was determined from the X-ray diffraction line-profile position and the microstrain from the diffraction-line broadening. The residual macrostress relaxed from 160 MPa to 30 MPa in the matrix crystallites and from 170 MPa to 50 MPa in the twin crystallites. Simultaneously with the decrease in macrostress the microstrain decreases significantly for both texture fractions. The strain relaxation behaviour is governed by movement and subsequent annihilation of defects in the layer.


1994 ◽  
Vol 339 ◽  
Author(s):  
A. Bachli ◽  
J. S. Chen ◽  
R. P. Ruiz ◽  
M-A. Nicolet

ABSTRACTThe thermally induced solid-phase reaction of 135 nm thick sputter-deposited W films with polycrystalline CVD-grown diamond substrates is investigated. The samples are annealed in vacuum (5×10/-7 torr) at temperatures between 700 °C and 1100 °C for 1 hour and examined by 2 MeV 4He++ backscattering spectrometry, x-ray diffraction, and scanning electron microscopy.The as-deposited W films contain roughly 5 at.% oxygen. After annealing the samples at 800 °C this oxygen concentration falls below the detection limit of less than 1 %. Incipient W2C phase formation occurs during annealing at 900 °C. The final state, the WC phase, is reached after annealing at 1100 °C.


2004 ◽  
Vol 19 (1) ◽  
pp. 74-76 ◽  
Author(s):  
E. Eiper ◽  
R. Resel ◽  
C. Eisenmenger-Sittner ◽  
M. Hafok ◽  
J. Keckes

Elevated-temperature X-ray diffraction (XRD) was used to evaluate residual stresses in aluminum thin films on Si(100). The films with a thickness of 2 μm were deposited by magnetron sputtering at different temperatures, and XRD measurements were carried out with the heating stage DHS 900 mounted on a Seifert 3000 PTS diffractometer. The strains were characterized always in temperature cycles from room temperature up to 450 °C with steps of 50 °C. Stress values in weakly textured thin films were calculated using the Hill model, applying temperature-dependent X-ray elastic constants of aluminum. The thin films exhibit specific temperature hysteresis of stresses depending on the deposition temperature (being from the range of 50 °C–300 °C). The results allow us to quantify contributions of intrinsic and extrinsic stresses to the total stress in the layers as well as to evaluate phenomena related to plastic yield. The comparison of the data from thin films deposited at different temperatures indicate a dependence of intrinsic stresses on the substrate temperature during deposition as well as the presence of the plastic yield in films during the cool-down after deposition


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