Tantalum disulfide nanobelts: preparation, superconductivity and field emission

Abstract

A large number of single-crystalline TaS2 nanobelts have been prepared via a two-step method. In this approach, TaS3 nanobelts as precursors were synthesized via chemical vapour transition (CVT), and pyrolysed into TaS2 nanobelts in vacuum. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the TaS2 nanobelts have a rectangular section of ∼15 × 40 to 80 × 900 nm2, and length up to several centimetres. Magnetic measurement indicated that the TaS2 nanobelts have superconductivity at 2.7 K, and the superconducting transition temperature (Tc) is higher than that (Tc = 0.8 K) reported for the bulk 2H-TaS2. The current density in electron field emission reached about 100 µA cm−2 at an applied field of about 27 V µm−1, so the nanobelts could be used as electronic field emitters.

Single‐Step Synthesis and Surface‐Assisted Growth of Superconducting TaS2 Nanowires

“…[18] However, TaS 2 nanobelts prepared from the heating of TaS 3 under vacuum were reported to adopt the 6R structure. [16] Analysis of SAED patterns for the nanowires found that the 112 0 diffraction spots were coincident with the long axis of the nanowires, indicating that growth occurs along the h112 0i directions.…”

“…[16] Both of these methods are two-step syntheses involving a trisulfide precursor. In the former report, the sensitivity of the nanomaterials to the electron beam prevented a determination of the crystal structure of the nanotubes and nanowires, whereas in the latter report, the TaS 2 nanobelts were found to adopt the rarely observed 6R polytype structure (R3 m).…”

“…[16] Bulk 6R-TaS 2 has been reported to exhibit superconductivity, with T c = 2.3 K at ambient pressure and T c > 4 K at 17.3 kbar. [21] As discussed with respect to 6R-TaS 2 nanobelts [16] based on the arguments of by Friend and Yoffe, [22] the increased transition temperatures of the nanomaterials, relative to that of the bulk material, could originate from a suppression of the periodic lattice distortion that drives charge density wave formation. A similar mechanism leads to an enhancement of the transition temperature of bulk 2H-TaS 2 following intercalation (T c = 2-5.5 K) or the application of pressure.…”

Superconducting tantalum disulfide nanotapes; growth, structure and stoichiometry

“…TaS3 is known to be thermodynamically stable at lower temperatures and thermally decomposes at higher temperatures into TaS2. 16 The stoichiometry and crystal structure of 2 is currently under further investigation. Product 3 took the form of high aspect 50 ratio nanowires and as the main focus of this paper, is discussed in more detail below.…”

Micro- and nanowires of iodine-containing Cu4Bi4S9

“…During last years, nanostructured simple sulphides [2][3][4] and metal sulphosalts [5][6][7] have been synthesized and studied aiming for their potential applications as advanced materials and devices in rather diverse fields such as electronics, optics, photonics, catalysis and medicine [8][9][10][11][12]. Since the chemical and physical properties of the compounds are influenced by their dimensions, shaping sulphides in forms of nanorods [4,13], nanowires [14,15], nanobelts [3], with a reduced dimensionality, becomes important for both fundamental and applied research.…”