May. 14, 2012

Strain Mapping at Al-Pb Interfaces

This Transmission Electron Microscope (TEM) investigation uses the retrieved complex exit-wave function in combination with the geometric phase analysis (GPA) to analyze strain located at faceted Al-Pb hetero-interfaces. It was found that the outer regions of a Pb nanoparticle were strained (compressed) which explains, according to the Clapeyron equation, an elevated melting in terms of interface strain.
moreAug. 30, 2010

Catalyst Characterization: TEM vs. STEM

In (HR)TEM images of catalysts, it is often difficult to recognize metal nanoparticles with a diameter around 1 nm or below on strongly scattering crystalline oxides. For such systems, the combination of information obtained with an aberration-corrected STEM microscope equipped with BF, DF and secondary electron detectors provides a superior means to detect the nanoparticles, as demonstrated here for Pt particles on cerium oxide. moreJun. 23, 2010

Single Carbon Atom Chains

80kV- High Resolution Transmission Electron Microscopy (HRTEM) characterization of micromechanically cleaved graphene shows in real- time atomically resolved dynamics of the carbon atoms in graphene constrictions. During electron irradiation, processes of hole formation generate graphene constrictions and eventually lead to stable single carbon atom chains. Carbon chains also occur between carbonaceous adsorbates and looping along graphene edges. moreApr. 19, 2010

Formation of α-Manganese Dioxide Nanotubes

Hydrothermal decomposition of KMnO4 in the acidic environment in the presence of Fe3+(aq) ions leads to the formation of α-MnO2 nanotubes. The morphology evolution from the sponge-like spheres to the nanotubes as a function of reaction time was imaged by FE-SEM and TEM. The presence of iron in nanotubes was unambiguously confirmed by STEM-EELS measurement across the nanotube diameter.

Introduction
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