Silicon nanocone arrays with metal silicide (Fe and Cr)-enriched apexes are fabricated on Si (100) substrate by the Ar+ ion bombardment method. The nanocone arrays show excellent field emission properties. A high current density (J) of ~0.33 mA/cm2 under a field of ~3 V/\mu m, a very low turn-on field of ~1.4 V/\mu m, and a very large enhancement factor of ~9466 are also obtained. The emission J of Si nanocone arrays remains extremely stable for long periods of time (24 h).