Ultrathin, High-Aspect Ratio, and Free-Standing Magnetic Nanowires by Exfoliation of Ferromagnetic Quasi-One-Dimensional van der Waals Lattices

Abstract

Driven by numerous discoveries of novel physical properties and integration into functional devices, interest in onedimensional (1D) magnetic nanostructures has grown tremendously. Traditionally, such structures are accessed with bottom-up techniques, but these require increasing sophistication to allow precise control over crystallinity, branching, aspect ratio, and surface termination, especially when approaching the subnanometer regime in magnetic phases. Here, we show that mechanical exfoliation of bulk quasi-one-dimensional crystals, a method similar to those popularized for two-dimensional van der Waals (vdW) lattices, serves as an efficient top-down method to produce ultrathin freestanding nanowires that are both magnetic and semiconducting. We use CrSbSe 3 as a representative quasi-1D vdW crystal with strong magnetocrystalline anisotropy and show that it can be exfoliated into nanowires with an average cross-section of 10 ± 2.8 nm. The CrSbSe 3 nanowires display reduced Curie−Weiss temperature but higher coercivity and remanence than the bulk phase. The methodology developed here for CrSbSe 3 , a representative for a vast class of 1D vdW lattices, serves as a blueprint for investigating confinement effects for 1D materials and accessing functional nanowires that are difficult to produce via traditional bottom-up methods.

Toward Extremely Fast Charging through Boosting Intercalative Redox Pseudocapacitance: A SbCrSe3 Anode for Large and Fast Sodium Storage

“…Raman spectrum presents three distinct peaks at 144, 173, and 211 cm ‐1 (Figure 2b), which correspond to the A g +B g , B g , and A g vibration modes of SbCrSe 3 , respectively. [ 37 ] Thermogravimetric (TG) and differential thermal analysis (DTA) curves show that the melt point of SbCrSe 3 is close to 1184 K (Figure 2c). X‐ray photoelectron spectroscopy (XPS) is further applied to investigate the chemical environment in SbCrSe 3 (Figure 2d–f).…”

The Structure and Magnetic Properties of a New Family of 1D Chromium Thiolate Coordination Polymers

“…[45][46][47][48] These freestanding wires are often low in symmetry, with mixed chalcogenide oxidation states and susceptibility to torsion resulting in non-uniform and poorly characterized metal environments in the bulk. Van der Waals solids in the hexagonal perovskite family such as BaxCrSy, 43 CoCaO3, 24 and others such as CrSbSe3 25 exhibit analogous stacked structures, however with mixed D3d and D3h metal coordination. Inconsistent experimental spin values in these systems are proposed to arise from mixed field splitting which, along with convoluting interchain coupling, often complicates magnetic interpretation.…”

“…14 Additionally more tractable and controllable coupling schemes have made 1 and 2D systems highly desirable magnetic models for several decades. [15][16][17][18] Many approaches to design low dimensional magnetic materials have been taken including coordination polymers (CPs) of ions as well as single molecules, [19][20][21][22][23] Van der Waals solids, 24,25 and cluster chemistries. [26][27][28] However, thus far the majority of these 1D materials are not highly symmetric, often containing skewed zig-zag motifs, 29,30 multiple magnetic sites 31 , or alternating metal coordination geometries.…”

High electron mobility and wide-bandgap properties in a novel 1D PdGeS3 nanochain

“…25,26 Recently, Qu et al also prepared 1D magnetic and semiconducting CrSbSe 3 nanowires by solution exfoliation, where the studies showed that 1D magnetic CrSbSe 3 nanowires exhibited increased coercivity and remanence compared to the bulk. 27 In addition to the exfoliation method, chemical vapor deposition, ultrahigh vacuum molecular beam epitaxy, and template-based self-assembly inside carbon nanotubes (CNTs) have also been used to synthesize specific 1D nanowires, such as transition-metal chalcogenide nanowires with a formula of M 6 X 6 (M = Mo or W and X = S, Se, or Te). [28][29][30] More notably, theoretical calculation is becoming a powerful method in material studies, which can effectively predict the feasibility of preparation, stability of structure, physical and chemical properties, and potential applications in practical devices.…”