Methods to partially reduce a niobium metal oxide and oxygen reduced niobium oxides

Abstract

Methods to at least partially reduce a niobium oxide are described wherein the process includes heat treating the niobium oxide in the presence of a getter material and in an atmosphere which permits the transfer of oxygen atoms from the niobium oxide to the getter material, and for a sufficient time and at a sufficient temperature to form an oxygen reduced niobium oxide. Niobium oxides and/or suboxides are also described as well as capacitors containing anodes made from the niobium oxides and suboxides.

1 . A capacitor anode comprising a niobium oxide having an atomic ratio of niobium to oxygen of 1:less than 2.5 and being formed at a formation voltage of about 6 volts or higher.  
     
     
         2 . The capacitor anode of  claim 1 , wherein said capacitor anode is formed at a formation voltage of from about 6 to about 130 volts.  
     
     
         3 . The capacitor anode of  claim 1 , wherein said capacitor anode is formed at a formation voltage of from about 75 volts to about 130 volts.  
     
     
         4 . The capacitor anode of  claim 1 , wherein said capacitor anode is formed at a formation voltage of from about 75 volts to about 100 volts.  
     
     
         5 . The capacitor anode of  claim 1 , wherein said DC leakage is less than 15 nA/CV, wherein said DC leakage is determined at a sintering temperature of 1300° C. for 10 minutes and a formation temperature of 60° C.  
     
     
         6 . The capacitor anode of  claim 5 , wherein said DC leakage is less than about 12 nA/CV.  
     
     
         7 . The capacitor anode of  claim 3 , wherein said DC leakage is less than 15 nA/CV.  
     
     
         8 . A niobium oxide having an atomic ratio of niobium to oxygen of 1 less than 2.5, and having a nitrogen content of from about 31,000 ppm N 2  to about 130,000 ppm N 2 .  
     
     
         9 - 31 . (canceled)