Rietveld texture analysis from TOF neutron diffraction data

2010 ◽  
Vol 25 (3) ◽  
pp. 283-296 ◽  
Author(s):  
H.-R. Wenk ◽  
L. Lutterotti ◽  
S. C. Vogel
Keyword(s):  
Neutron Diffraction ◽  
Texture Analysis ◽  
Electron Backscatter Diffraction ◽  
Computer Code ◽  
Preferred Orientation ◽  
Complex Data ◽  
Ambient Conditions ◽  
Science Center ◽  
Step Procedure ◽  
Backscatter Diffraction

One of the advantages of a multidetector neutron time-of-flight diffractometer such as the high pressure preferred orientation diffractometer (HIPPO) at the Los Alamos Neutron Science Center is the capability to measure efficiently preferred orientation of bulk materials. A routine experimental method for measurements, both at ambient conditions, as well as high or low temperatures, has been established. However, only recently has the complex data analysis been streamlined to make it straightforward for a noninitiated user. Here, we describe the Rietveld texture analysis of HIPPO data with the computer code Materials Analysis Using Diffraction (MAUD) as a step-by-step procedure and illustrate it with a metamorphic quartz rock. Postprocessing of the results is described and neutron diffraction results are compared with electron backscatter diffraction measurements on the same sample.

scholarly journals Using electron backscatter diffraction to measure full crystallographic orientation in Antarctic land-fast sea ice

2018 ◽  
Vol 64 (247) ◽  
pp. 771-780 ◽  
Author(s):  
PAT WONGPAN ◽  
DAVID J. PRIOR ◽  
PATRICIA J. LANGHORNE ◽  
KATHERINE LILLY ◽  
INGA J. SMITH
Keyword(s):  
Sea Ice ◽  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Preferred Orientation ◽  
Angle Distribution ◽  
Crystal Preferred Orientation ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
First Time ◽  
Platelet Ice

ABSTRACTWe have mapped the full crystallographic orientation of sea ice using electron backscatter diffraction (EBSD). This is the first time EBSD has been used to study sea ice. Platelet ice is a feature of sea ice near ice shelves. Ice crystals accumulate as an unconsolidated sub-ice platelet layer beneath the columnar ice (CI), where they are subsumed by the advancing sea–ice interface to form incorporated platelet ice (PI). As is well known, in CI the crystal preferred orientation comprises dominantly horizontal c-axes, while PI has c-axes varying between horizontal and vertical. For the first time, this study shows the a-axes of CI and PI are not random. Misorientation analysis has been used to illuminate the possible drivers of these alignments. In CI the misorientation angle distribution from random pairs and neighbour pairs of grains are indistinguishable, indicating the distributions are a consequence of crystal preferred orientation. Geometric selection during growth will develop the a-axis alignment in CI if ice growth in water is fastest parallel to the a-axis, as has previously been hypothesised. In contrast, in PI random-pair and neighbour-pair misorientation distributions are significantly different, suggesting mechanical rotation of crystals at grain boundaries as the most likely explanation.

Transpressional deformation in the mantle below the North Anatolian fault system, Turkey

2020 ◽  
Author(s):  
Basil Tikoff ◽  
Vasili Chatzaras ◽  
Timothy Chapman ◽  
Naomi Barshi ◽  
Ercan Aldanmaz ◽  
...  
Keyword(s):  
Fault Zone ◽  
Electron Backscatter Diffraction ◽  
Preferred Orientation ◽  
North Anatolian Fault ◽  
Mantle Xenoliths ◽  
Fault System ◽  
Alkali Basalts ◽  
Crystallographic Preferred Orientation ◽  
The North ◽  
Backscatter Diffraction

<p>The North Anatolian Fault Zone (NAFZ) is a 1200-km-long, dextral intracontinental transform fault zone, and initiated ca. 13–11 Ma ago.  The NAFZ formed in response to the N-S convergence of the Eurasian and Arabian plates, accommodated by the westward motion of the Anatolia plate relative to Eurasia plate.  Mantle xenoliths were sampled in late Miocene (11.68±0.25 to 6.47±0.47 Ma) alkali basalts and basanites, immediately N of the trace of the North Anatolian fault, and were previously interpreted to sample the mantle portion of the North Anatolian fault/shear zone at depth.  The studied xenoliths are mainly spinel lherzolites and harzburgites.  Equilibration temperatures estimated from two-pyroxene geothermometers range from 775 to 975 °C, while pressures estimated from the Cr in clinopyroxene geobarometer and pseudosection modelling range from 12 to 22 kbar, which correspond to depths of 40–80 km.  We used high‐resolution X-ray computed tomography to quantify the xenolith fabric defined by the 3D shape preferred orientation of spinel grains.  Spinel displays dominantly oblate fabric ellispoids, consistent with flattening strain.  Olivine has two main crystallographic preferred orientation patterns, the axial-[010] and the A-type, determined with electron backscatter diffraction.  The axial-[010] pattern is consistent with the spinel fabric and other microstructures that show flattening strains.  To further constrain the strain path, we analyze the crystallographic vorticity axes in olivine, which show a complex pattern.  Our results are consistent with an interpretation of transpressional deformation in the upper mantle below the NAFZ, during the early stages of the development of the transform system.  Transpressional deformation is consistent with collision-induced, strike-slip extrusion of Anatolia.</p>

scholarly journals Texture analysis of melt-spun Ni-Mn-Ga tapes by means of electron backscatter diffraction (EBSD)

2010 ◽  
Vol 200 (8) ◽  
pp. 082013 ◽  
Author(s):  
A Koblischka-Veneva ◽  
M R Koblischka ◽  
J Schmauch ◽  
A Mitra ◽  
A K Panda
Keyword(s):  
Texture Analysis ◽  
Electron Backscatter Diffraction ◽  
Melt Spun ◽  
Electron Backscatter ◽  
Backscatter Diffraction
Sign in / Sign up

Export Citation Format

Share Document