2 research outputs found
Investigation of a Monturaqui Impactite by Means of Bi-Modal X-ray and Neutron Tomography
X-ray and neutron tomography are applied as a bi-modal approach for the 3D characterisation of a Monturaqui impactite formed by shock metamorphism during the impact of an iron meteorite with the target rocks in the Monturaqui crater (Chile). The particular impactite exhibits structural heterogeneities on many length scales: its composition is dominated by silicate-based glassy and crystalline materials with voids and Fe/Ni-metal and oxihydroxides particles generally smaller than 1 mm in diameter. The non-destructive investigation allowed us to apply a novel bi-modal imaging approach that provides a more detailed and quantitative understanding of the structural and chemical composition compared to standard single mode imaging methods, as X-ray and neutron interaction with matter results in different attenuation coefficients with a non-linear relation. The X-ray and neutron data sets have been registered, and used for material segmentation, porosity and metallic content characterization. The bimodal data enabled the segmentation of a large number of different materials, their morphology as well as distribution in the specimen including the quantification of volume fractions. The 3D data revealed an evaporite type of material in the impactite not noticed in previous studies. The present study is exemplary in demonstrating the potential for non-destructive characterisation of key features of complex multi-phase objects such as impactites
Solution Epitaxial Growth of Cobalt Nanowires on Crystalline Substrates for Data Storage Densities beyond 1 Tbit/in<sup>2</sup>
The implementation of nano-objects
in numerous emerging applications
often demands their integration in macroscopic devices. Here we present
the bottom-up epitaxial solution growth of high-density arrays of
vertical 5 nm diameter single-crystalline metallic cobalt nanowires
on wafer-scale crystalline metal surfaces. The nanowires form regular
hexagonal arrays on unpatterned metallic films. These hybrid heterostructures
present an important perpendicular magnetic anisotropy and pave the
way to a high density magnetic recording device, with capacities above
10 Terabits/in<sup>2</sup>. This method bypasses the need of assembling
and orientating free colloidal nanocrystals on surfaces. Its generalization
to other materials opens new perspectives toward many applications