Electrical Conductivity of Sintered Chromia Mixed with TiO2, CuO and Mn-Oxides

Abstract

Abstract: The electrical conductivity of sintered Cr2O3 mixed with 2% and 5% (in molar fraction) TiO2 or CuO was investigated in the temperature range 500~900℃ in air and in Ar/4 vol. pct H2 atmospheres. The effect of different Mn-oxides on the electrical conductivity of Cr2O3 was also studied under the same conditions. From the conductivity measurements it is established that additions of TiO2 change the defect structure of Cr2O3 and the effect of TiO2 on the electrical conductivity is controlled by TiO2 concentration as well as temperature and O2 partial pressure of the surrounding atmosphere. The conductivity of Cr2O3 increased in air and decreased in the Ar/H2 atmosphere by CuO additions. The effect of CuO was discussed with possible changes in the defect concentration in Cr2O3. Mixing of Cr2O3 with different Mn-oxides at the same Mn to metal atom fraction decreased the conductivity in air and in Ar/H2 atmospheres. No clear correlation between the spinel fraction and the changes in conductivity could be found.

Key words: Electrical conductivity, Cr2O3, Mixing with TiO2, CuO, Mn-oxides

K.El-Menshawy, H.P.Buchkremer, F.Tietz, D.Stoever. Electrical Conductivity of Sintered Chromia Mixed with TiO2, CuO and Mn-Oxides[J]. J Mater Sci Technol, 2006, 22(02): 245-251.

References

[1]K.Huang,P.Y.Hou and J.B.Goodenough:Mater.Res. Bull,2001,36,81.
[2]K.Huang,P.Y.Hou and J.B.Goodenough:Solid State Ionics,2000,129,237.
[3]F.Tietz,H.P.Buchkremer and D.Stover:Solid State Ionics,2002,152-153,373.
[4]T.Brylewski,M.Nanko,T.Maruyama and K.Przybylski:Solid State Ionics,2001,143,131.
[5]T.Maruyama,M.Nanko,T.Brylewski and M.Tanaka: Proc.26th Fall meeting of Japan Petroleum Institute, Kyoto,Japan,November 13,1996.
[6]T.Maruyama,T.Brylewski,M.Nanko and K.Przybylski:Proc.Fifth Int.Symp.on Solid Oxide Fuel Cells,Aachen,Germany,June 2-5,Julich,1997.
[7]T.Brylewski:Rep.31 st International Course for Ad- vanced Research in Chemistry and Chemical Engineer- ing at Tokyo Institute of Technology,Tokyo,Japan, 1996.
[8]P.H.Hou,K.Huang and W.T.Bakke:in Proc.6 th Int.Symp.on Solid Oxide Fuel Cells (SOFC- VI),The Electrochemical Society,Pennington,NJ,eds. S.C.Singhal and M.Dokiya,1999,737.
[9]Th.Malkow,V.Von der Crone,A.M.Laptev,T.Koppitz,U.Breuer and W.J.Quadakkers:in Proc. 5th Int.Symp.on Solid Oxide Fuel Cells (SOFC- V),eds.S.C.Singhal,H.Tagawa and W.Lehnert,The Electrochemical Society,Pennington,NJ,1997,1244.
[10]Y.Miyake,Y.Akiyama,T.Yasuo,S.Taniguchi, M.Kadowaki and K.Nishio:Proc.Fuel Cell Semi- nar,Orlando,1996,17-20,36.
[11]W.J.Quadakkers,T.Mallkow,J.Piron-Abellan, V.Flesch,V.Shemet and L.Singheiser:in Proc.4th Europ.SOFC Forum on The European Fuel Cell Forum,Oberrohrdorf,ed.A.J.Mcevoy,Switzerland, 2000,827.
[12]P.Kofstad and K.P.Lillerud:J.Electrochem.Soc, 1980,127,2410.
[13]A.Holt and P.Kofstad: Solid State Ionics,1994,69, 127.
[14]A.Holt and P.Kofstad: Solid State Ionics,1994,69, 137.
[15]T.Matsui and K.Naito:J.Nucl,Mater.,1984,120, 115.
[16]A.Holt and P.Kofstad:Solid State Ionics,1997,100, 201.
[17]A.Holt and P.Kofstad:Solid State Ionics,1999,117, 21.
[18]H.Nagai,TFujikawa and K.Shoji:T.Jpn.I.Met, 1983,24(8),581.
[19]H.Nagai,S.Ishikawa,N.Amanoand and K.Shoji:T. Jpn.J.Met,1985,26(10),753.
[20]H.Nagai and K.Ohayashi:J.Am.Ceram.Soc,1989, 72(3),400.
[21]R.F.Huang,A.K.Agarwal and H.U.Anderson:J.Am. Ceram.Soc,1984,67(2),146.
[22]V.Jayaraman,K.I.Gnanaseker and G.Praiaswani: Sensor.Actuator.,1999,B55,185. [23]S.Somiya,H.Hirano and S.Kamiya:J.Solid State Chem.,1978,25,273.
[24]A.Naoumidis,H.A.Schulze,W.Jungen and P.Lersch: J.Europ.Ceram.Soc,1991,7,55.
[25]M.Y.Su:Diss.Abstr.Int.,1988,48,3049.
[26]P.Kofstad:High Temperature Corrosion,Elsevier, London and New York,1988,114.
[27]D.B.Meadowcroft and N.A.Davies:Laboratory Note No.RD/LN201/72,Central Electricity Research Lab- oratories,Leather.Head,Survey,England.
[28]T.Matsui and K.Naito:J.Nucl.Mater.,1984 120, 115.
[29]K.Hauffe and J.Block:Z.Phys.Chem.,1951,198(5- 6),232.
[30]H.Nagai,M.Okabayashi and T.Murakami:T.Jpn.I. Met.,1982,23,473.
[31]J.S.Park and H.G.Kim:J.Am.Ceram.Soc,1988, 71,173.
[32]Y.V.Gollkov and V.F.Balakirev:J.Solid State Chem., 1987,17(2),562.
[33]D.H.Speidel and A.Muan:J.Am.Ceram.Soc,1963, 46(12),578.
[34]E.M.Levin and Howard F.McMurdie:Phase Diagrams of Ceramists,Compiled at the national Bureau of Standards,The American Ceramic Society,65 Ce- ramic Drive,Columbus,Ohio,USA,1975 Supplement.
[35]W.J.Quadakkers:Institute for Materials and Pro- cessing in Energy Systems,IWV-2,Research Centre Juelich GmbH,Juelich,Germany,Private Communi- cation.