title: Structural and chemical analysis of gadolinium halides encapsulated within WS2 nanotubes.
abstract: The hollow cavities of nanotubes serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of WS2 nanotubes by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is non-trivial due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.
authors.affiliation: International Iberian Nanotechnology Laboratory (INL), Avenida Mestre Jose Veiga, Braga 4715-330, Portugal. leonard.francis@inl.int.
authors.forename: E A
authors.initials: EA
authors.lastname: Anumol
authors.affiliation: Ural Federal University, Institute of Mathematics and Computer Sciences, Turgeneva Str., 4, 620083 Ekaterinburg, Russian Federation.
authors.forename: Andrey N
authors.initials: AN
authors.lastname: Enyashin
authors.affiliation: King Abdullah University of Science and Technology, Physical Science and Engineering Division, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Nitin M
authors.initials: NM
authors.lastname: Batra
authors.affiliation: King Abdullah University of Science and Technology, Physical Science and Engineering Division, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Pedro M F J
authors.initials: PM
authors.lastname: Costa
authors.affiliation: International Iberian Nanotechnology Laboratory (INL), Avenida Mestre Jose Veiga, Braga 4715-330, Portugal. leonard.francis@inl.int.
authors.forename: Francis Leonard
authors.initials: FL
authors.lastname: Deepak