HREM Observations of Mg2Si-Based Multilayers for Soft X-Ray Optics

1991 ◽  
Vol 49 ◽  
pp. 906-907
Author(s):  
A. R. Modak ◽  
David J. Smith ◽  
Z. G. Li ◽  
P. Boher ◽  
Ph. Houdy
Keyword(s):  
High Vacuum ◽  
Rf Sputtering ◽  
Ultra High Vacuum ◽  
Silicon Substrates ◽  
Ray Optics ◽  
X Ray ◽  
Long Period ◽  
The Past ◽  
X Ray Scattering ◽  
Short Period

Multilayers fabricated with alternating materials having significant differences in X-ray scattering powers are being investigated for applications in soft X-ray optics. Multilayers consisting of combinations of W, Rh, Fe, Si3N4, SiO2 and Si, C, B4C have been studied in the past. Mg2Si based multilayer structures are theoretically efficient reflectors of wavelengths above the Mg-Kα line (9.89 Å) and the Mg-Lα line (251.5 Å) because of their low absorption in the respective wavelength regimes due to the presence of magnesium. In the present study, Mg2Si based multilayers fabricated on silicon substrates by ultra high vacuum rf sputtering have been characterized by HREM. W, Si, and Mg2Si targets in conjunction with the introduction of nitrogen were employed to deposit alternate Mg2Si and W or Si3N4 layers. We report here our preliminary observations of a characteristic short period W/Mg2Si layered structure used above the Mg-Kα line and two long period multilayers based on W/Mg2Si and Si3N4/Mg2Si used above the Mg-Lα line.

From ultra-high vacuum to the electrochemical interface: X-ray scattering studies of model electrocatalysts

2009 ◽  
Vol 140 ◽  
pp. 41-58 ◽  
Author(s):  
Christopher A. Lucas ◽  
Michael Cormack ◽  
Mark E. Gallagher ◽  
Alexander Brownrigg ◽  
Paul Thompson ◽  
...  
Keyword(s):  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray ◽  
X Ray Scattering ◽  
Electrochemical Interface ◽  
Ray Scattering

Ultra-High Vacuum Grazing Incidence Small Angle X-Ray Scattering Camera for in Situ Surface Analysis

1993 ◽  
Vol 37 ◽  
pp. 413-418
Author(s):  
Joanne Levine Parrill ◽  
Jerome B. Cohen ◽  
Yip-Wah Chung
Keyword(s):  
Surface Analysis ◽  
Small Angle ◽  
High Vacuum ◽  
Grazing Incidence ◽  
Ultra High Vacuum ◽  
X Ray ◽  
X Ray Scattering ◽  
Position Sensitive ◽  
Ray Scattering

AbstractAn ultra-high vacuum chamber designed for in situ grazing incidence small angle x-ray scattering (GISAXS) surface analysis is described. Unique features of this equipment are the precision rotary feedthrough for angular alignment of the sample, the sample heating design, the Be window arrangement, and the compatibility of this chamber with both a rotating anode and a synchrotron beamline. This chamber was used as part of a GISAXS camera utilizing a 18 kW Rigaku rotating anode, pin-hole collimation, and a position sensitive detector. The resolution of this camera was 0.007 A-1 with a 1.4 mm wide beamstop and CuKα

Multi-use high/low-temperature and pressure compatible portable chamber forin situgrazing-incidence X-ray scattering studies

2013 ◽  
Vol 20 (3) ◽  
pp. 474-481 ◽  
Author(s):  
Pilar Ferrer ◽  
Juan Rubio-Zuazo ◽  
Catherine Heyman ◽  
Fatima Esteban-Betegón ◽  
Germán R. Castro
Keyword(s):  
Heat Exchanger ◽  
High Vacuum ◽  
Grazing Incidence ◽  
Ultra High Vacuum ◽  
Operating Pressure ◽  
X Ray ◽  
Heater Element ◽  
X Ray Scattering ◽  
Set Up ◽  
Ray Scattering

The multipurpose portable ultra-high-vacuum-compatible chamber described in detail in this article has been designed to carry out grazing-incidence X-ray scattering techniques on the BM25-SpLine CRG beamline at the ESRF. The chamber has a cylindrical form, built on a 360° beryllium double-ended conflate flange (CF) nipple. The main advantage of this chamber design is the wide sample temperature range, which may be varied between 60 and 1000 K. Other advantages of using a cylinder are that the wall thickness is reduced to a minimum value, keeping maximal solid angle accessibility and keeping wall absorption of the incoming X-ray beam constant. The heat exchanger is a customized compact liquid-nitrogen (LN2) continuous-flow cryostat. LN2 is transferred from a storage Dewar through a vacuum-isolated transfer line to the heat exchanger. The sample is mounted on a molybdenum support on the heat exchanger, which is equipped with a BORALECTRIC heater element. The chamber versatility extends to the operating pressure, ranging from ultra-high vacuum (<10−10 mbar) to high pressure (up to 3 × 103 mbar). In addition, it is equipped with several CF ports to allocate auxiliary components such as capillary gas-inlet, viewports, leak valves, ion gun, turbo pump,etc., responding to a large variety of experiment requirements. A movable slits set-up has been foreseen to reduce the background and diffuse scattering produced at the beryllium wall. Diffraction data can be recorded either with a point detector or with a bi-dimensional CCD detector, or both detectors simultaneously. The system has been designed to carry out a multitude of experiments in a large variety of environments. The system feasibility is demonstrated by showing temperature-dependence grazing-incidence X-ray diffraction and conductivity measurements on a 20 nm-thick La0.7Ca0.3MnO3thin film grown on a SrTiO3(001) substrate.

scholarly journals Laser power meters as an X-ray power diagnostic for LCLS-II

2018 ◽  
Vol 25 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Philip Heimann ◽  
Stefan Moeller ◽  
Sergio Carbajo ◽  
Sanghoon Song ◽  
Georgi Dakovski ◽  
...  
Keyword(s):  
Free Electron Laser ◽  
Laser Power ◽  
High Vacuum ◽  
Average Power ◽  
Gas Analysis ◽  
Ultra High Vacuum ◽  
Beam Path ◽  
X Ray ◽  
High Repetition ◽  
Residual Gas

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. A number of characteristics in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.

Morphological basis for the complex melting behaviour of isotactic polystyrene

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Mahmoud Al-Hussein ◽  
Gert Strobl
Keyword(s):  
Morphological Changes ◽  
Melting Behaviour ◽  
Temperature Dependent ◽  
Molten Material ◽  
Scanning Calorimetry ◽  
Isotactic Polystyrene ◽  
X Ray ◽  
Long Period ◽  
X Ray Scattering ◽  
Increasing Temperature

AbstractTemperature-dependent small-angle X-ray scattering spectroscopy of isothermally cold crystallized isotactic polystyrene revealed considerable morphological reorganization during subsequent heating to the melt. Both the crystalline thickness and the long period increased continuously with increasing temperature before the samples finally melted. The temperature dependence of these changes correlated very well with the melting behaviour observed with differential scanning calorimetry. As the temperature increased during a heating scan, the initial lamellae that formed during isothermal crystallization showed only little reorganization until they started to melt. Then, the molten material recrystallized continuously into increasingly thicker lamellae at increasing temperature until they finally melted. As the crystallization temperature approached the final melting temperature of the recrystallized lamellae, the initial lamellae melted without further recrystallization and no morphological changes were seen in this case.

Analysis Of Sige Fet Device Structures On Silicon-on-sapphire Substrates by X-Ray Diffraction

1998 ◽  
Vol 533 ◽  
Author(s):  
P. M. Mooney ◽  
J. O. Chu ◽  
J. A. Ott ◽  
J. L. Jordan-Sweet ◽  
B. S. Meyerson ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Device Fabrication ◽  
Ultra High Vacuum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Wafer Cleaning ◽  
Device Structures

AbstractSi/Si1-xGex, heterostructures on improved silicon-on-sapphire substrates were grown epitaxially by ultra-high vacuum chemical vapor deposition for application as p-channel field effect transistors. High-resolution triple-axis x-ray diffraction was used to analyze these structures quantitatively and to evaluate the effects of device fabrication processes on them. Out-;diffusion of Ge from the Si1-xGex, quantum well was observed after fabrication as was the change in thickness of the Si cap layer due to wafer cleaning and gate oxidation at 875 °C

Structrual Characterization and Raman Scattering of Epitaxial Aluminum Nitride Thin Films on Si(111)

1992 ◽  
Vol 242 ◽  
Author(s):  
W. J. Meng ◽  
T. A. Perry ◽  
J. Heremans ◽  
Y. T. Cheng
Keyword(s):  
Thin Films ◽  
Aluminum Nitride ◽  
Raman Scattering ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Sputter Deposition ◽  
Transmission Electron ◽  
Substrate Temperatures

ABSTRACTThin films of aluminum nitride were grown epitaxially on Si(111) by ultra-high-vacuum dc magnetron reactive sputter deposition. Epitaxy was achieved at substrate temperatures of 600° C or above. We report results of film characterization by x-ray diffraction, transmission electron microscopy, and Raman scattering.

The crossover of preferred orientation in TiN film growth: A real time x-ray scattering study

1997 ◽  
Vol 12 (1) ◽  
pp. 9-12 ◽  
Author(s):  
J. H. Je ◽  
D. Y. Noh ◽  
H. K. Kim ◽  
K. S. Liang
Keyword(s):  
Real Time ◽  
Film Growth ◽  
Substrate Surface ◽  
Rf Sputtering ◽  
Growth Front ◽  
Surface Topology ◽  
Ex Situ ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The orientational crossover phenomena in a radio-frequency (rf) sputtering growth of TiN films were studied in a real-time synchrotron x-ray scattering experiment. Following the initial random nucleation and growth stage, the growth was dominated by the grains with the (002) planes aligned with the substrate surface. Surprisingly, at later stages, the grains with the (002) growth front tilted away from the surface by about 60° became dominant. The tilting of the growth front resulted in a faceted surface topology that was confirmed by an ex situ AFM study. Our x-ray results suggest that the crossover was driven by the competition between the surface and the strain energy

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