Targeting One- and Two-Dimensional Ta–Te Structures via Nanotube Encapsulation

Abstract

Fine control over material synthesis on the nanoscale can facilitate the stabilization of competing crystalline structures. Here we demonstrate how carbon nanotube reaction vessels can be used to selectively create one-dimensional TaTe 3 chains or two-dimensional TaTe 2 nanoribbons with exquisite control of the chain number or nanoribbon thickness and width.Transmission electron microscopy and scanning transmission electron microscopy reveal the detailed atomic structure of the encapsulated materials. Complex superstructures such as multi-1 chain spiraling and apparent multi-layer moirés are observed. The rare 2H phase of TaTe 2 (1H in monolayer) is found to be abundant as an encapsulated nanoribbon inside carbon nanotubes. The experimental results are complemented by density functional theory calculations for the atomic and electronic structure, which uncovers the prevalence of 2H-TaTe 2 due to nanotube-tonanoribbon charge transfer and size confinement. Calculations also reveal new 1T' type charge density wave phases in TaTe 2 that could be observed in experimental studies.

One-Dimensional Atomic Chains for Ultimate-Scaled Electronics

“…Besides, the single SnSe ACs encapsulated inside single-walled CNTs generate different crystalline forms as designed, including linear, zigzag, and helical (2 × 1) ACs . The nanotemplate approaches also allow us to explore the fundamental physics and chemistry based on 1D ACs, such as strain-mediated chain distortion, supermodulation of ordered defects, and selective phase transition . On the other hand, nanotemplate encapsulation blocks the 1D ACs from environmental-factor-induced degradations, enabled by the chemically inert nature of the nanotemplate shell.…”

“…58 The nanotemplate approaches also allow us to explore the fundamental physics and chemistry based on 1D ACs, such as strain-mediated chain distortion, 59 supermodulation of ordered defects, 60 and selective phase transition. 61 On the other hand, nanotemplate encapsulation blocks the 1D ACs from environmental-factor-induced degradations, enabled by the chemically inert nature of the nanotemplate shell. However, the passivation shell layer also possibly restricts using these buried ACs directly.…”

Surfactant-Assisted Isolation of Small-Diameter Boron-Nitride Nanotubes for Molding One-Dimensional van der Waals Heterostructures

“…One effective way to isolate these nanotubes’ structurally refined single walls is through the use of existing stable tubules as templates. So far, CNTs have been increasingly used as templates for the growth of various 1D materials such as atomic wires, − molecular arrays, − and chalcogenides. − Recent developments of the coaxial growth of 1D van der Waals (vdW) heterostructures have demonstrated that single-walled (SW) MoS 2 NTs can be templated outside CNTs by chemical vapor deposition (CVD) . The CNT-templated reaction has become a standard for the synthesis and stabilization of guest nanotubes.…”

Solving Complex Nanostructures With Ptychographic Atomic Electron Tomography

“…While electron microscopy has played an important role in the identification and characterization of the encapsulated phases, the detailed 3D structure of the interior nanowire is not always clear. For example, the encased material's structure often exhibits a dependence on the diameter of the nanotube [22], and can form complex threedimensional structures inside the CNT, such as coreshell structures [26] and multilayer moiré structures [27].…”

“…Encapsulated Zr 11 Te 50 species are synthesized within CNTs using protocols similar to those for the growth of confined TaTe 2 , NbSe 3 , and HfTe 3 structures[21,22,27]. The Zr 11 Te 50 species can be synthesized following the synthesis of ZrTe 3 , where stoichiometric quantities of…”