Surface zone-axis patterns

1984 ◽  
Vol 42 ◽  
pp. 516-517
Author(s):  
J. A. Eades ◽  
M. D. Shannon ◽  
M. E. Meichle
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Incident Beam ◽  
Zone Axis ◽  
Surface Zone ◽  
Transmission Electron ◽  
Beam Orientation ◽  
Convergent Beam ◽  
Beam Diffraction

In electron diffraction from crystals, whether it be in reflection or transmission, the intensity of the emergent beams varies in a complex way with the angle that the incident beam makes with the crystal structure. The techniques for displaying this variation of intensity as a function of incident beam orientation have mostly been applied to zone-axis orientations, where the variation is particularly elaborate. The resulting patterns, known as zone-axis patterns or zaps, have become an important part of transmission electron microscopy.There are several techniques for obtaining zaps. The best known is convergent-beam diffraction but they can also be obtained in the form of bend-contour patterns and Tanaka patterns, and by rocking methods.

Citrate Stabilized Silver Nanoparticles

2011 ◽  
Vol 3 (3) ◽  
pp. 15-28 ◽  
Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Pushpa Raj Pudasaini ◽  
Shanna Pahl ◽  
Dulce Romero-Urbina
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Colloidal Solution ◽  
Measurement Techniques ◽  
Structural Defects ◽  
Potential Measurement ◽  
Transmission Electron

Citrate stabilized silver (Ag) colloidal solution were synthesized and characterized for crystallographic and surface properties by using transmission electron microscopy (TEM) and zeta potential measurement techniques. TEM investigation depicted the size of Ago ranges from 5 to 50 nm with smaller particles having single crystal structure while larger particles with structural defects (such as multiply twinned, high coalescence and Moire patterns). ?-potential measurement confirms the presence of Ag+ in nAg stock solution. The shift in ?-potential measurement by +25.1 mV in the filtered solution suggests the presence of Ag+ in Ago nanoparticles.

Crystallographic Features of Ferroelectric States around the Tetragonal /Rhombohedral Phase Boundary in Pb1-xLax(Zr1-yTiy)O3

2010 ◽  
Vol 638-642 ◽  
pp. 1737-1742
Author(s):  
Masazumi Arao ◽  
Yasuhide Inoue ◽  
Ryoutarou Ando ◽  
Yasumasa Koyama
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dielectric Properties ◽  
Phase Boundary ◽  
Rhombohedral Phase ◽  
Relaxor Behavior ◽  
Rotational Displacement ◽  
Transmission Electron ◽  
Ti Content

To understand dielectric properties around the ferroelectric tetragonal (FT)/rhombohedral (FR) phase boundary in Pb1-xLax(Zr1-yTiy)O3, the crystallographic features of ferroelectric states around the boundary have been investigated by transmission electron microscopy. It was found that, when the Ti content approached to the phase boundary in the FT-phase area, a dielectric property became the relaxor behavior. The corresponding change in the crystallographic features is that the usual FT state is converted into the nanometer-sized coexisting state of the ferroelectric monoclinic (FM) and FR phases. Because the crystal structure of FR-phase regions in the coexisting state involves the R25-type rotational displacement of oxygen octahedra, the FR phase can be identified as the low-temperature ferroelectric rhombohedral phase that is present in Pb(Zr1-yTiy)O3. It is thus understood that the relaxor behavior found in Pb1-xLax(Zr1-yTiy)O3 should be associated with the presence of the nanometer-sized coexisting state that consists of two ferroelectric phases.

Arrangements of Fe-Centered Zn12 Icosahedra in Fe-Zn Intermetallic Compounds Determined by Ultra-High Resolution Scanning Transmission Electron Microscopy

2015 ◽  
Vol 1760 ◽  
Author(s):  
Norihiko L. Okamoto ◽  
Akira Yasuhara ◽  
Katsushi Tanaka ◽  
Haruyuki Inui
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Single Crystal ◽  
Scanning Transmission Electron Microscopy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Deformation Properties ◽  
Scanning Transmission

ABSTRACTThe crystal structure of the δ1p phase in the Fe-Zn system has been refined by single-crystal synchrotron X-ray diffraction combined with ultra-high resolution scanning transmission electron microscopy. The crystal structure can be described to build up with Fe-centered Zn12 icosahedra. The deformation properties obtained by single-crystal micropillar compression tests of the δ1p phase is discussed in terms of the arrangement of the Fe-centered Zn12 icosahedra in contrast with the ζ phase in the Fe-Zn system.

Lack of a threefold rotation axis in α-Fe2O3and α-Cr2O3crystals

2015 ◽  
Vol 71 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Michał Stękiel ◽  
Radosław Przeniosło ◽  
Izabela Sosnowska ◽  
Andrew Fitch ◽  
Jacek B. Jasiński ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rotation Axis ◽  
Magnetic Ordering ◽  
Evidence Based ◽  
Space Group ◽  
X Ray ◽  
Space Groups ◽  
Transmission Electron

The crystal structure of α-Fe2O3and α-Cr2O3is usually described with the corundum-type trigonal crystal structure based on the space group R\bar 3c. There are, however, some observations of the magnetic ordering of both α-Fe2O3and α-Cr2O3that are incompatible with the trigonal symmetry. We show experimental evidence based on X-ray powder diffraction and supported by transmission electron microscopy that the symmetry of the crystal structure of both α-Fe2O3and α-Cr2O3is monoclinic and it is described with the space groupC2/c(derived from R\bar 3c by removing the threefold rotation axis). The magnetic orderings of α-Fe2O3and α-Cr2O3are compatible with the magnetic space groupsC2/candC2/c′, respectively. These findings are in agreement with the idea from Curie [(1894),J. Phys.3, 393–415] that the dissymmetry of the magnetic ordering should be associated with a dissymmetry of the crystal structure.

(111)p microtwinning in SrRuO3 thin films on (001)p LaAlO3

2009 ◽  
Vol 65 (6) ◽  
pp. 694-698 ◽  
Author(s):  
Y. Han ◽  
I. M. Reaney ◽  
D. S. Tinberg ◽  
S. Trolier-McKinstry
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Orientation Relationship ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Zone Axis ◽  
Laser Deposition ◽  
Transmission Electron ◽  
Diffraction Patterns

SrRuO3 (SRO) thin films grown on (001)p (p = pseudocubic) oriented LaAlO3 (LAO) by pulsed laser deposition have been characterized using transmission electron microscopy. Observations along the 〈100〉p directions suggests that although the SRO layer maintains a pseudocube-to-pseudocube orientation relationship with the underlying LAO substrate, it has a ferroelastic domain structure associated with a transformation on cooling to room temperature to an orthorhombic Pbnm phase (a − a − c + Glazer tilt system). In addition, extra diffraction spots located at ±1/6(ooo)p and ±1/3(ooo)p (where `o' indicates an index with an odd number) positions were obtained in 〈110〉p zone-axis diffraction patterns. These were attributed to the existence of high-density twins on {111}p pseudocubic planes within the SrRuO3 films rather than to more conventional mechanisms for the generation of superstructure reflections.

Preparation and Luminescence Properties of ZnS: Cu/Fe Nanocrystalline

2014 ◽  
Vol 1033-1034 ◽  
pp. 1054-1057
Author(s):  
Xiang Zhang ◽  
Jin Liang Huang ◽  
Li Hua Li
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thioglycolic Acid ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Fe Nanoparticles

ZnS: Cu/Fe nanocrystals were synthesized by hydrothermal method with thioglycolic acid as a stabilizer. The phases, grain size and luminescent properties of the nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and fluorescence photometer respectively. The results showed that ZnS: Cu/Fe nanoparticles have a particle size about 7nm and possess a cubic zinc blende crystal structure. The luminous intensity of ZnS: Cu/Fe nanocrystals was strongly when they were reacted at 140°C for 12 hours.

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