HREM in solid-state chemistry and crystallography

1992 ◽  
Vol 50 (1) ◽  
pp. 104-105
Author(s):  
Lars Kihlborg ◽  
Margareta Sundberg ◽  
Gunnar Svensson
Keyword(s):  
Solid State ◽  
High Temperature Superconductors ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Solid State Chemistry ◽  
X Ray ◽  
Solid State Ionics ◽  
Resolution Electron ◽  
New Compounds

High-resolution electron microscopy has had a great impact on solid state chemistry. The possibility it offers of directly imaging the structure of solids has made it an unvaluable complement to conventional diffraction methods. Disorder and extended effects have become accessible to observation, superstructures, structural modulations and microphases can be identified and particles down to nanometer size can be studied. Combined with electron diffraction and x-ray microanalysis it is a powerful tool for phase analysis, giving guidance to synthesis of new compounds. Under certain conditions even chemical reactions can be studied in situ at atomic resolution. Numerous examples in be found in the fields of high-temperature superconductors, zeolites, ferroelectrics and solid state ionics.

scholarly journals In situ X-ray diffraction computed tomography studies examining the thermal and chemical stabilities of working Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes during oxidative coupling of methane

2020 ◽  
Vol 22 (34) ◽  
pp. 18964-18975
Author(s):  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Simon D. M. Jacques ◽  
Vesna Middelkoop ◽  
Gavin Vaughan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Solid State ◽  
Oxidative Coupling ◽  
Structural Changes ◽  
Oxidative Coupling Of Methane ◽  
Membrane Reactors ◽  
Solid State Chemistry ◽  
X Ray Diffraction ◽  
X Ray

In situ XRD-CT and post-reaction SEM/EDX were used to study the solid-state chemistry and structural changes of Ba0.5Sr0.5Co0.8Fe0.2O3−δ membrane reactors during the oxidative coupling of methane reaction.

Hydrogen Desorption Reactions of the Na-Mg-B-H System

2010 ◽  
Vol 72 ◽  
pp. 164-169 ◽  
Author(s):  
Daphiny Pottmaier ◽  
Sebastiano Garroni ◽  
Maria Dolors Barò ◽  
Marcello Baricco
Keyword(s):  
Solid State ◽  
Research And Development ◽  
Ball Milling ◽  
Powder Diffraction ◽  
Hydrogen Desorption ◽  
X Ray ◽  
New Compounds ◽  
Desorption Reaction

Hydrogen storage in the solid state has shown increasing research and development, and recently an approach in mixing two hydride systems together by ball milling (reactive hydride composites) has been investigated in more detail, e.g. NaBH4 plus MgH2. Thermodynamic destabilization may occur by new compounds formation during dehydrogenation, e.g. MgB2. A study of the the role of O2/H2O contamination for the reaction 2NaBH4 + MgH2 ↔ 2NaH + MgB2 + 4H2 was conducted using in-situ X-ray powder diffraction. Desorption reaction is observed to begin by a competition of MgH2 and NaBH4 decomposition due to higher reactivity promoted by ball milling processing summed to O2/H2O contamination. Oxidation of NaBH4 into NaBO2 is observed to happen in higher degree than MgH2/Mg into MgO for the Na-Mg-B-H system.

Atomic-Resolution Electron Microscopy of TiB2 Precipitates in an Industrial TiAl Alloy

1996 ◽  
Vol 466 ◽  
Author(s):  
B. J. Inkson ◽  
G. Möbus ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Tial Alloy ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Resolution Electron ◽  
B2 Phase ◽  
Relationship Of ◽  
Orientational Relationship

ABSTRACTTiB2 nano-lamellae, grown in-situ within a TiAl intermetallic melt, have been examined by high resolution electron microscopy. The use of the Stuttgart ARM enables Ti and B columns to be distinguished in the HREM images. Examination of the internal structure of the T1B2 platelets reveals extensive prismatic faulting on {1010}TiB2, {0110}TiB2 and {1100}TiB2 planes. Externally, the TiB2 platelets exhibit an orientational relationship {1010}TiB2 // {001}B2 and [0001]TiB2 // <010>B2 with interleaving platelets of B2-phase, with the predominating interface planes being {1010}TiB2 // {001}B2. The minor facets of the TiB2 platelets are [0001]TiB2 // <010>B2. {0110}TiB2 and {1100}TiB2, with the latter two facets showing no relationship with the interleaving B2-phase. No preferred orientation relationship of the TiB2 with the surrounding γ-TiAl and α2-Ti3Al phases is observed.

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