One-dimensional (1D) conducting materials are of great
interest
as potential building blocks for integrated nanocircuits. Ternary
1D transition-metal chalcogenides, consisting of M6X6 wires with intercalated A atoms (M = Mo or W; X = S, Se,
or Te; A = alkali or rare metals, etc.), have attracted
much attention due to their 1D metallic behavior, superconductivity,
and mechanical flexibility. However, the conventional solid-state
reaction usually produces micrometer-scale bulk crystals, limiting
their potential use as nanoscale conductors. Here we demonstrate a
versatile method to fabricate indium (In)-intercalated W6Te6 (In–W6Te6) bundles with
a nanoscale thickness. We first prepared micrometer-long, crystalline
bundles of van der Waals W6Te6 wires using chemical
vapor deposition and intercalated In into the crystal via a vapor-phase
reaction. Atomic-resolution electron microscopy revealed that In atoms
were surrounded by three adjacent W6Te6 wires.
First-principles calculations suggested that their wire-by-wire stacking
can transform through postgrowth intercalation. Individual In–W6Te6 bundles exhibited metallic behavior, as theoretically
predicted. We further identified the vibrational modes by combining
polarized Raman spectroscopy and nonresonant Raman calculations.