Controllable dimensionality conversion between 1D and 2D CrCl3 magnetic nanostructures

Abstract

The fabrication of one-dimensional (1D) magnetic systems on solid surfaces, although of high fundamental interest, has yet to be achieved for a crossover between two-dimensional (2D) magnetic layers and their associated 1D spin chain systems. In this study, we report the fabrication of 1D single-unit-cell-width CrCl3 atomic wires and their stacked few-wire arrays on the surface of a van der Waals (vdW) superconductor NbSe2. Scanning tunneling microscopy/spectroscopy and first-principles calculations jointly revealed that the single wire shows an antiferromagnetic large-bandgap semiconducting state in an unexplored structure different from the well-known 2D CrCl3 phase. Competition among the total energies and nanostructure-substrate interfacial interactions of these two phases result in the appearance of the 1D phase. This phase was transformable to the 2D phase either prior to or after the growth for in situ or ex situ manipulations, in which the electronic interactions at the vdW interface play a nontrivial role that could regulate the dimensionality conversion and structural transformation between the 1D-2D CrCl3 phases.

Efficient Synthesis of Highly Crystalline One-Dimensional CrCl3 Atomic Chains with a Spin Glass State

“…When the block CrCl 3 with 3D spatial periodicity and symmetry is encapsulated in the finite space of carbon nanotubes, the spatial domain-limiting effect enables it to maintain only a 1D state in the finite space, which can easily cause the spatial symmetry to break down. Since the structure of CrCl 3 is not centrosymmetric, the Dzyaloshinskii–Moriya (DM) interaction usually contributes to the magnetic phase transition and leads to a canted spin arrangement, which is consistent with the previously reported quasi-1D CrCl 3 nanoribbons exhibiting antiferromagnetic coupling …”

“…Since the structure of CrCl 3 is not centrosymmetric, the Dzyaloshinskii−Moriya (DM) interaction usually contributes to the magnetic phase transition and leads to a canted spin arrangement, which is consistent with the previously reported quasi-1D CrCl 3 nanoribbons exhibiting antiferromagnetic coupling. 42 Furthermore, in order to determine the cause of the magnetic phase transition in Figure 4a, the temperature dependence of alternating current (ac) magnetization at various frequencies (f) was measured to provide insight into the magnetic dynamics. In Figure 4c, the peak of the imaginary part (χ″) is observed at a low frequency of 1 Hz, centered at 2.4 K, and shifting toward higher temperatures with increasing frequency.…”

1D Magnetic MX3 Single‐Chains (M = Cr, V and X = Cl, Br, I)

“…For single‐chain CrCl 3 synthesized on NbSe 2 substrates, charge transfer may similarly aid stabilization of the chain structure. [ 6 ] In addition, our calculations show that the magnetic states of MX 3 single‐chains are strongly affected by electron doping. Figure 3f shows the magnetic energy as a function of electron doping.…”

“…Moreover, although some quasi‐1D magnetic materials have received modest attention, the synthesis of fully isolated, truly 1D single‐chain magnets has proven difficult. In a promising recent advancement, [ 6 ] some single CrCl 3 chains were observed amongst collections of multi‐chain CrCl 3 bundles grown on NbSe 2 substrates. Synthesis and further experimental studies of such structures are exceedingly challenging because of the sensitivity of halide materials to light, oxygen, and moisture.…”

Observations of Charge-Density-Wave States in W6Te6 Wires

“…The exploration of 1D vdW materials started with the discovery of carbon nanotubes (CNTs), which possess intriguing electrical properties and 1D morphology with diameters of subnanometers. , However, CNTs are limited by the complex chirality and mixing of metallic/semiconducting behaviors. Beyond CNTs, several types of vdW (quasi)-1D materials have attracted growing interest, such as elemental nanowires (e.g., Te and P chains), , transition metal chalcogenides (e.g., M 6 X 6 , MX 3 , and M 2 X 9 where M represents transition metal and X represents chalcogen), − and transition metal halides (e.g., CoI 2 and CrCl 3 ). , Compared to CNT, these newly developed materials possess uniquely defined structures, making their properties more controllable. Among these vdW 1D materials, the recently rediscovered transitional metal monochalcogenide (TMM) M 6 X 6 (M = Mo, W and X = S, Se, Te) nanowires provide an intriguing platform for investigating the 1D physics since isolated few TMM wires and even single TMM wires have been achieved by both top-down (i.e., electron-beam irradiation and chemical dissolution) and bottom-up (i.e., molecular beam epitaxy) methods.…”