Methods to partially reduce a niobium metal oxide and oxygen reduced niobium oxides
AssigneeCabot Corporation
InventorsJonathon L. Kimmel, Ricky W. Kitchell., James A. Fife
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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.
Claims40
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, and having a DC leakage of less than 15 nA/CV wherein said DC leakage is determined from an anode sintered at 1500° C. for 10 minutes and formed at a formation temperature of 60° C.
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, and having a capacitance of 40,000 CV/g or greater at a sintering temperature of from about 1200° C. to about 1600° C. for 10 minutes and at a formation temperature of 85° C.
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 and having a capacitance of 20,000 CV/g or greater, wherein said capacitance is determined at a sintering temperature of 1300° C. for 10 minutes and at a formation temperature of 85° C.
A capacitor anode comprising a niobium oxide having an atomic ratio of niobium to oxygen of 1:
- less than 2.5, wherein the powder forming the capacitor anode has a burning rate of less than 5 mm/s.
A capacitor anode comprising a niobium oxide having an atomic ratio of niobium to oxygen of 1:
- less than 2.5, and having a minimum ignition energy of 100 mJ or greater.
A method of forming a capacitor anode comprising a niobium oxide having an atomic ratio of niobium to oxygen of 1:
- less than 2.5, comprising forming said niobium oxide into the shape of an anode and sintering at a temperature of from about 1200° C. to about 1600° C. for a time of from about 1 minute to about 30 minutes;
- anodizing at from about 16 to about 75 volts at a formation temperature of about 85° C.;
- annealing said anode at a temperature of from about 300 to about 350° C. for a time of from about 10 minutes to about 60 minutes;
- and
- manganizing said anode at a temperature of from about 220° to 28° C.
A method to at least partially reduce a niobium oxide, comprising heat treating a starting niobium oxide in the presence of a getter material in an atmosphere permitting the transfer of oxygen atoms from the starting niobium oxide to the getter material for a sufficient time and sufficient temperature such that the starting niobium oxide and said getter material form an oxygen reduced niobium oxide.
Dependencies are inferred from the claim text.