Synthesis and Properties of Single-Crystal FeSi Nanowires

Abstract

We report for the first time the chemical synthesis of free-standing single-crystal nanowires (NWs) of FeSi, the only transition-metal Kondo insulator and the host structure for ferromagnetic semiconductor Fe(x)Co(1-x)Si. Straight and smooth FeSi nanowires are produced on silicon substrates covered with a thin layer of silicon oxide through the decomposition of the single-source organometallic precursor trans-Fe(SiCl3)2(CO)4 in a simple chemical vapor deposition process. Unlike typical vapor-liquid-solid (VLS) NW growth, FeSi NWs form without the addition of metal catalysts, have no catalyst tips, and depend strongly on the surface employed. X-ray spectroscopy verifies the identity and the room-temperature metallic nature of FeSi NWs. Room-temperature electrical transport measurements using NW devices show an average resistivity of 210 micro Omega cm, similar to the value for bulk FeSi. Investigations into the low-temperature physical properties of the first one-dimensional Kondo insulator and the possible new NW growth mechanism are underway. This unique synthetic approach to FeSi NWs will be generally applicable to many other transition-metal silicides.

Growth of Crystalline Copper Silicide Nanowires in High Yield within a High Boiling Point Solvent System

“…The coupling capacitance was calculated at 7.7 aF µm -1 with an inductance of 0.43 pH µm -1 . The NWs presented here compare well with many other NW silicide interconnect alternatives in terms of resistivity (FeSi 210 µΩ cm, 52 Ti 5 Si 4 114 µΩ cm, 53 TaSi 2 210 µΩ cm 11 , CoSi 510 µΩ cm 54 ) but remain some way behind those noted for NiSi NWs (10 µΩ cm) 8 and CoSi 2 NWs (30 µΩ cm). 55 Further analysis will focus on effective current density carrying ability, carrier propagation speed and lower power dissipation, as these are the main requirements for a viable interconnect material.…”

Solid-state synthesis of embedded single-crystal metal oxide and phosphate nanoparticles and in situ crystallization

“…The molecular precursor route to nanostructured materials both in solution [16][17][18] or in the solid-state [19,20] is an unconventional, yet suitable, way to obtain metallic, metal-oxidic and semiconducting nanoparticles and nanostructures. Organometallic derivatives, both cyclic and polymeric phosphazenes, are emerging as useful precursors of metallic nanostructured materials.…”

Synthesis and Applications of Noble Metal and Metal Silicide and Germanide 1-Dimensional Nanostructures

“…Also, Jin group introduced metal organic chemical vapor deposition (MOCVD) system to grow metal silicide such as FeSi, CoSi and Mn 19 Si 33 NWs. [37][38][39] To fabricate a variety of single-crystalline metal silicide NWs, we employed CVT method where anhydrous metal halide beads and Si substrate or Si powder act as a metal source and a Si source, respectively. By using the CVT approach, we can synthesized not only many metal silicide NWs including MnSi, CrSi 2 , Fe 1-x Co x Si NWs, [40][41][42] but composition modulated cobalt silicides (CoSi, Co 2 Si, and Co 3 Si) 43 and iron silicides (FeSi and Fe 5 Si 3 ) NWs.…”