scholarly journals THE DIRECT DETERMINATION OF STACKING FAULTS SEQUENCE IN ZnS POLYTYPE BY HIGH RESOLUTION ELECTRON MICROSCOPY

1982 ◽  
Vol 31 (5) ◽  
pp. 664
Author(s):  
KANG ZHEN-CHUAN
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Stacking Faults ◽  
Direct Determination ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

Interaction Between Basal Stacking Faults and Prismatic Inversion Domain Boundaries in GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Philomela Komninou ◽  
Joseph Kioseoglou ◽  
Eirini Sarigiannidou ◽  
George P. Dimitrakopulos ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
High Energy ◽  
Low Energy ◽  
Inversion Domain ◽  
Resolution Electron ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.

High Resolution Electron Microscopy of Sintered Ain

1982 ◽  
Vol 40 ◽  
pp. 546-547
Author(s):  
G. Van Tendeloo ◽  
G. Thomas
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
High Resolution ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
Tetrahedral Coordination ◽  
Temperature Behaviour ◽  
Resolution Electron ◽  
Suitable Form ◽  
Metal Ratio

Sialon ceramics are widely studied because of their industrial interest due to their high temperature behaviour. AIN, being one of the edge components, has obtained little attention up until now mainly because it is difficult to prepare in a suitable form; moreover, it is a very poor sintering material. Very little is known about the properties or the exact structure. Recently Komeya and Tsuge succeeded in sintering 90wt% A IN and 10wt% SiO2 at 2100°. All the known tetrahedral A IN polytypes are based on the 2H (wurtzite type) structure where A1 and N are in tetrahedral coordination. When the metal to non-metal ratio deviates from one, different polytypes are formed by creating periodic stacking faults every nth layer.

Microstructural determination of a metastable phase during rhodium oxidation

1989 ◽  
Vol 47 ◽  
pp. 262-263
Author(s):  
A. David Logan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Volume Expansion ◽  
Lattice Structure ◽  
Metastable Phase ◽  
Active Surface ◽  
High Resolution Electron Microscopy ◽  
Silica Spheres ◽  
Resolution Electron

In heterogeneous catalysis, oxidation of the catalyst is frequently used as a means of removing impurities from the active surface. However, bulk oxidation severely alters the microstructure of the metal due to atom repositioning and valence changes. Transformation of Rh to Rh2O3 causes the lattice structure to change from fcc to hexagonal with a resulting volume expansion of 90% due to density changes. This is the reported cause for fracturing of crystallites and variations in reactivity. In this study, microstructural changes during progressive oxidation of 5 nm metal Rh particles have been examined.A 2 wt% Rh/Silica catalyst was prepared using Rh(III)-2,4 pentanedionate as a precursor and nonporous silica spheres as a support. The catalyst was then reduced in flowing H2 at 473 K. High resolution electron microscopy (HREM) was performed on a JEM-4000EX having a point resolution of 0.17 nm. The catalyst was oxidized in research purity O2 (Matheson 99.99%) using an all glass volumetric chemisorption system.

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