Growth of Large-Area Aligned Molybdenum Nanowires by High Temperature Chemical Vapor Deposition:  Synthesis, Growth Mechanism, and Device Application

Abstract

Large-area aligned Mo nanowires have been grown on stainless steel substrates by high-temperature chemical vapor deposition with the use of Mo metal. The detailed physical and chemical growth processes regarding the formation of the nanowires have been investigated using mass spectroscopy, thermogravimetry, and differential scanning calorimetry analysis, as well as structure analysis by electron microscopy. In reference to Gibbs energy calculation, our study reveals that the growth relies on the decomposition of MoO 2 vapors through condensation of its vapor at high substrate temperatures. The aligned growth is a result of competing growth with the nanowires normal to the substrate surface reaching the final growth front. The field emission measurement and the vacuum luminescent tube study show that the Mo nanowires have potential application as electron emitters.

Fabrication of vertically aligned single-crystalline lanthanum hexaboride nanowire arrays and investigation of their field emission

“…A similar mode was also observed in the growth of Mo nanowire arrays. 27 To illustrate the proposed mechanism, the samples were studied after different reaction times of 5, 10, 15 and 30 min (shown in Supplementary Figure S4). Although Supplementary Figure S4 does not provide in situ or in-time illustration, the results agree relatively well with the overall sketch.…”

Systematic Study of the Growth of Aligned Arrays of α-Fe2O3 and Fe3O4 Nanowires by a Vapor–Solid Process

“…The straight line indicates that the field-emission behavior follows the F-N mechanism where the electrons can tunnel through the potential barrier from conduction band to a vacuum state. The F-N relationship can be simply expressed by Equation 2 [48] J = (Ab 2 E 2 / U) exp (-BU 3/2 / bE) (2) where U is the work function; A and B are constants corresponding to 1.56 × 10 -10 AV -2 eV and 6.83 × 10 3 VeV -3/2 lm -1 , respectively; b is the field-enhancement factor, which is used to indicate the degree of the field-emission enhancement of any tip shape on a planar surface; and b is a parameter depending on the geometry of the NW, crystal structure, and the density of the emitting points. It is worth pointing out that two slopes are found at the low-and high-field regions in the J-E and F-N plots.…”

“…Metallic NWs are applicable as interconnects for nanodevices, semiconductor NWs can be used to fabricate transistors and electro-optical devices, [1][2][3][4][5] and magnetic 1D nanomaterials have received much attention because of their potential applications in perpendicular data recording and spintronic devices. [6,7] Among magnetic materials, iron oxides, such as a-Fe 2 O 3 and Fe 3 O 4 , are the most popular materials and possess many advantages in technological applications.…”

Highly conductive vertically aligned molybdenum nanowalls and their field emission property

“…In the recent years, one has seen a large number of studies focused on the preparation of one-dimensional molybdenum oxide nanostructures, such as MoO 2 nanorods [7], pinaster-like MoO 2 nanoarrays [8], and MoO 2 nanostars [9], with a few cases on two-dimensional (2D) molybdenum oxide nanostructures such as MoO 3 nanobelts [10]. Our group has been developing a thermal vapor deposition method for synthesizing vertically well-aligned molybdenum oxide nanowires [11-14] and for a large-area preparation of 2D MoO 3 microbelts [15,16]. In this paper, we report that uniform Mo nanowalls can be grown on various substrates by simple thermal vapor deposition.…”