The ability to image and quantify material behavior in real time at nano to near-macro length scales, preferably in three dimensions, is a crucial feature of modern materials science. Here, we examine such an approach to characterize the mechanical properties of three diverse classes of materials: (1) biological materials, principally bone, using both in situ small-/wide-angle x-ray scattering/diffraction to probe nanoscale deformation behavior and x-ray computed microtomography to study microscale damage mechanisms; (2) biomimetic materials, specifically a nacre-like ceramic, where microtomography is used to identify toughening mechanisms; (3) synthetic materials, specifically ceramic textile composites, using in situ microtomography to quantify the salient mechanical damage at ultrahigh temperatures. The mechanistic insights for the understanding of damage evolution and fracture afforded by these techniques are undeniable; as such, they can help provide a basis for the achievement of enhanced damage tolerance in structural materials.

Nitrogen-doped multiwalled carbon nanotube (CNT) bundles exhibiting pine-tree-like morphologies were synthesized on silicon–silicon oxide (Si/SiO2) substrates using a pressure-controlled chemical vapor deposition process. Electron field emission (FE) measurements showed a notable emission improvement at low turn-on voltages for the CNT pine-like morphologies (e.g., 0.59 V/µm) in comparison with standard aligned N-doped CNTs (>1.5 V/µm). We envisage that these pine-tree-like structures could be potentially useful in the fabrication of efficient FE and photonic devices.

Yttrium–aluminum garnet doped with Ce was plasma sprayed using two different processes – gas-stabilized plasma torch and water-stabilized plasma torch. Coatings on various substrate materials (stainless steel, ceramics, YAG undoped crystals), as well as self-standing plates, were obtained. The coatings adhered on materials with relatively large variety of thermal expansion coefficient. Besides microstructural, crystallographic, and thermal-stability investigations, numerous optical tests were performed. They included cathodoluminescence (CL), UV-VIS-NIR reflectance, and response of the Ce:YAG on light with various wave lengths. After spraying, the desired YAG crystalline phase sustained without any decomposition, but an amorphous fraction was present in both types of coatings. Selected coatings were heat-treated to crystallize fully and change their optical properties. Minor amorphous fraction crystallized at 930 °C. The heat-treated coatings exhibited higher CL and also larger visible emission when illuminated with a 366 nm lamp. Microhardness of the coatings was tested as well and proved the mechanical similarity of both coating types and difference from the single crystal. The optical responses of the coatings were influenced by imperfections like splat boundaries, pores, and thin cracks, which were healed only partly by heat treatment. However, the Ce:YAG was first plasma sprayed and moreover produced by both spray techniques without an irreversible loss of the desired garnet phase.