Method for Low Temperature Production of Nano-Structured Iron Oxide Coatings

Abstract

The present invention provides a method for forming nano-structured iron oxide coatings on a substrate. The method includes the steps of: (a) subjecting a chamber containing a plasma source to vacuum; (b) feeding iron pentacarbonyl and O 2 into a chamber containing a plasma source, wherein the O 2 is fed into the chamber at a rate greater than that of the iron pentacarbonyl; (c) subjecting the substrate to the chamber, wherein the substrate is at a temperature less than 250° C., thereby forming an iron oxide coating on the substrate, wherein the iron oxide is greater than 90 percent in the α-hematite form.

1 . A method of forming an iron oxide coating on a substrate, wherein the method comprises the following steps: 
 (a) subjecting a chamber containing a plasma source to vacuum;    (b) feeding iron pentacarbonyl and O 2  into a chamber containing a plasma source, wherein the O 2  is fed into the chamber at a rate at least 4 times greater than that of the iron pentacarbonyl;    (c) subjecting the substrate to the chamber, wherein the substrate is at a temperature less than 250° C.    thereby forming an iron oxide coating on the substrate, wherein the coating is greater than 500 Å thick, and wherein the iron oxide is greater than 90 percent in the α-hematite form.    
   
   
       2 . The method according to  claim 1 , wherein the iron pentacarbonyl is fed into the chamber at a rate of at least 10 sccm.  
   
   
       3 . The method according to  claim 1 , wherein the plasma source is a high density argon plasma source.  
   
   
       4 . The method according to  claim 1 , wherein the substrate comprises a spectrally transparent cyclic olefin polymer.  
   
   
       5 . The method according to  claim 1 , wherein the substrate is at a temperature less than 200° C.  
   
   
       6 . The method according to  claim 1 , wherein the coating on the substrate is greater than 750 Å thick.  
   
   
       7 . The method according to  claim 1 , wherein the iron oxide coating is greater than 95 percent in the α-hematite form.  
   
   
       8 . The method according to  claim 1 , wherein the O 2  is fed into the chamber at a rate at least 8 times greater than that of the iron pentacarbonyl.  
   
   
       9 . The method according to  claim 8 , wherein the plasma source is a high density argon plasma source.  
   
   
       10 . The method according to  claim 9 , wherein the substrate is at a temperature less than 175° C.