Transport properties and growth parameters of PdC and WC nanowires prepared in a dual-beam microscope

Abstract

In this work we investigate the electrical transport properties and growth conditions of tungsten carbon (WC) and palladium carbon (PdC) nanostructures on Si substrates using a focused ion beam and scanning electron microscope. In situ energy dispersive x-ray (EDX) characterizations reveal that electron-beam-induced WC and PdC nanostructure depositions (EBID) show a lower metal concentration (below 3% atomic percentage) than in ion-beam-induced deposition (IBID) (above 20%). In the case of PdC the growth pattern and the Pd/C content were optimized by adjusting the deposition temperature of the precursor material. In situ measurements of the resistivity of the nanostructures as a function of thickness reveal a minimum at a thickness approximately 200 nm. The lowest resistivity obtained for the PdC and WC structures is two orders of magnitude higher than the corresponding bulk values for pure Pd and W. The EBID samples show a non-metallic behaviour due to the low metal content. The temperature and magnetic field dependence of the IBID structures reveal a behaviour similar to disordered or granular conductors. The upper critical field and critical current density of the WC structures were measured below the superconducting critical temperature of approximately 5 K.

Identifying the crossover between growth regimes via in-situ conductance measurements in focused electron beam induced deposition

“…At this point it is worth mentioning that the conductivity can be further increased by employing focused ion beam induced deposition (FIBID) in combination with the precursor W(CO) 6 . Metallic tungsten-based FIBID structures which are also known to become superconducting below 5.2 K, [34][35][36][37] exhibit conductivity values up to 400-680 kS/m exceeding the values for tungsten-based FEBID structures reported here by a factor of 30-50 [34,36,38]. The difference of conductivity between samples prepared by means of FEBID and FIBID is, however, not inherent to deposits fabricated by the dissociation of W(CO) 6 .…”

Trends in stability, elastic and electronic properties of cubic Rh, Ir, Pd and Pt carbides depending on carbon content: MC versus M4C from first-principles calculations

“…Alongside the nitrides mentioned above, a series of investigations of noble metal carbides also has been carried out [9][10][11][12][13][14][15][16][17][18][19][20][21]. The most extensively examining material among them is platinum carbide (PtC), which was successfully synthesized at high pressure and high temperature by the laser-heated diamond anvil cell technique [9].…”

“…Electronic, thermodynamic and elastic properties of some possible polymorphs of PtC (rock-salt (B1), zinc-blende (B3), wurtzite (B4), nickel-arsenide (B8) and PbO (B10) structures) are discussed [10][11][12][13][14][15][16][17][18]. Besides, some experimental data are available for Pd x C 1 À x granular films and nanostructures [19,20], and theoretical simulations were performed for PdC [12,18] and IrC [15,21].…”

Luminescence and electrical properties of single ZnO/MgO core/shell nanowires

“…1(d). This material is nearly insulating; 8 besides fixing the single NW it provides a good thermal contact of the NW to the substrate. In the following step, the substrate is covered with a resist (PMMA 950 K) for the electron beam lithography process.…”