Metal silicide nanowires and methods of their production

Abstract

The present invention provides metal silicide nanowires, including metallic, semiconducting, and ferromagnetic semiconducting transition metal silicide nanowires. The nanowires are grown using either chemical vapor deposition (CVD) or chemical vapor transport (CVT) on silicon substrates covered with a thin silicon oxide film, the oxide film desirably having a thickness of no greater than about 5 nm and, desirably, no more than about 2 nm (e.g., about 1-2 nm). The metal silicide nanowires and heterostructures made from the nanowires are well-suited for use in CMOS compatible wire-like electronic, photonic, and spintronic devices.

What is claimed is: 
     
         1 . A metal silicide nanowire having an average diameter of no more than about 100 nm and a length of at least 200 nm, wherein the nanowire is free-standing in that it is not supported along its length by a substrate, and further wherein the metal silicide is a titanium silicide, a manganese silicide, a platinum silicide, a molybdenum silicide, a ruthenium silicide, a tungsten silicide, a palladium silicide, or a vanadium silicide. 
     
     
         2 . The nanowire of  claim 1 , wherein the metal silicide is a titanium silicide. 
     
     
         3 . The nanowire of  claim 2 , wherein the metal silicide is TiS 2 . 
     
     
         4 . The nanowire of  claim 1 , wherein the metal silicide is a manganese silicide. 
     
     
         5 . The nanowire of  claim 4 , wherein the metal silicide is MnSi, MnSi 1.8 , or both. 
     
     
         6 . The nanowire of  claim 1 , wherein the metal silicide is a platinum silicide. 
     
     
         7 . The nanowire of  claim 6 , wherein the metal silicide is PtSi. 
     
     
         8 . The nanowire of  claim 1 , wherein the metal silicide is a molybdenum silicide. 
     
     
         9 . The nanowire of  claim 8 , wherein the metal silicide is MoSi 2 , Mo 5 Si 3 , or both. 
     
     
         10 . The nanowire of  claim 1 , wherein the metal silicide is a ruthenium silicide. 
     
     
         11 . The nanowire of  claim 10 , wherein the metal silicide is Ru 2 Si 3 . 
     
     
         12 . The nanowire of  claim 1 , wherein the metal silicide is a tungsten silicide. 
     
     
         13 . The nanowire of  claim 12 , wherein the metal silicide is WSi 2 , W 5 Si 3 , or both. 
     
     
         14 . The nanowire of  claim 1 , wherein the metal silicide is a palladium silicide. 
     
     
         15 . The nanowire of  claim 14 , wherein the metal silicide is Pd 2 Si. 
     
     
         16 . The nanowire of  claim 1 , wherein the metal silicide is a vanadium silicide. 
     
     
         17 . The nanowire of  claim 16 , wherein the metal silicide is V 3 Si, VSi 2 , or both. 
     
     
         18 . The nanowire of  claim 1 , wherein the nanowire is free of metal catalyst impurities. 
     
     
         19 . The nanowire of  claim 1 , wherein the nanowire is a single crystal nanowire. 
     
     
         20 . The nanowire of  claim 1 , wherein the nanowire lacks a catalyst cap or tip.