Patent ID: 7655497

Claim:
A method for growth of an alloy for use in a nanostructure, the method comprising: providing a substrate comprising Si, on which is deposited at least one of (i) a thin film coating of Au and (ii) a spaced apart array of thin particles of at least one of Au, Ni, Ti, Cr, In, Sb, Ge and Te, having a thickness in a range of 0.5-100 nm, with a substrate temperature in a range of about 330° C.-550° C., where at least a portion of the thin film coating or thin particle array serves as a catalyst for growth of nanostructures on a selected surface of the substrate; providing at least first and second chemical sources, with the first source comprising Ge w Te x and the second source comprising Sb y Te z , where the numbers w, x, y and z have substantially the ratios w:x and y:z=2:2 and 2:3, respectively, and where the first and second sources each have source temperatures in a range 450° C.≦T≦720° C., adjacent to the substrate; allowing at least a portion of the first source and at least a portion of the second source to become first and second vapors, respectively, and to combine to form a resulting vapor comprising Ge p Sb q Te r , where p, q and r are positive numbers in ranges permitted by oxidization states associated with the respective elements Ge, Sb and Te, where the numbers p, q and r have substantially the ratios p:q:r=2:2:5; and exposing the selected surface of the substrate to the vapor comprising Ge p Sb q Te r for a selected time interval, whereby at least one nanostructure is grown on the selected surface.