SnO2所具有表面擴散與高溫蒸發凝結的特性導致其燒結緻密化困難。對SnO2:Sb2O3、SnO2:CuO與SnO2:Sb2O3:CuO三種系列成分在1300℃燒結之實驗發現，Sb2O3的摻雜對SnO2導電性質的提升可有顯著的效果。在SnO2:Sb2O3系列中，2 mol % Sb2O3的摻雜可降低SnO2室溫電阻率約6個數量級之多，達1.21×10-2 Ω-cm，然而卻會造成燒結緻密化的更加惡化，此系列試片之相對密度僅為55～57%左右。另一方面，以CuO作為助燒結劑，只需少量（0.5 mol %）便能達成96%相對密度以上的高緻密化效果，但電阻率量測結果顯示對SnO2導電性質有負面影響，其室溫電阻率升高約2～3個數量級。
　　實驗結果顯示Sb－Cu－O系統在高溫下的反應中， ＝1～2之試片仍可達92%以上之相對密度，顯示在900℃時Sb2O3與CuO之間形成CuSb2O6的反應並不致於耗盡成分中的CuO。
　　兼具高度緻密化與良好導電性的試片可在2 mol% Sb2O3－2 mol% CuO之添加比例得到，其相對密度為94.8%，而室溫電阻率為2.54×10-2 Ω-cm。結果顯示Sb2O3對燒結緻密性與CuO對導電性質的負面效應，可以藉由兩者的適當比例添加達到相互補償的效果。亦即，在SnO2中添加Sb2O3與CuO，可在達到高緻密度的情況之下，仍保留良好的導電性質。

　　The poor sintering capacity of SnO2 is characterized as the non-densifying mechanisms such as surface diffusion and evaporaton-
condensation. Samples of SnO2:Sb2O3, SnO2:CuO and SnO2:Sb2O3: CuO composition systems were investigated as sintered at 1300℃ for 2 hours, the results show that doping with Sb2O3 can effectively decrease the room-temperature resistivity of SnO2 by about 6 orders of magnitude. In the SnO2:Sb2O3 system, specimen doped with 2 mol% Sb2O3 shows the lowest resistivity of 1.21×10-2 Ω-cm. However, the dopant is found to further deteriorate densification of SnO2, which all samples of this system show a low relative density ranged from 55 to 57%.
　　It is found that CuO can largely promote the densification of SnO2 during sintering. Adding a small amount (0.5 mol% ) of CuO can raise the relative density of samples up to more than 96%. However, the measured values of resistivity indicate that the effect caused by CuO on conductivity is negative.
　　In the SnO2:Sb2O3:CuO composition system it is found that the samples of ＝1～2 in present study still show high values of relative density over 92% after sintering. This result suggests that the formation reaction of CuSb2O6 occurs at about 900℃may not completely consume CuO in specimens.
　　Finally, materials combined high density and good electrical conductivity are obtained by jointly adding Sb2O3 and CuO to SnO2. The lowest room-temperature resistivity of 2.54×10-2 Ω-cm as measured in specimen containing 2 mol% Sb2O3 and 2 mol% CuO is effectively densified to 94.8% relative density. The negative effects on densification due to addition of Sb2O3 and on conductivity caused by CuO seems can be compensated by jointly adding both of them.

1.D. Nisiro, G Fabbri, G.C. Celotti, A. Bellosi, Influence of the additives
　and processing conditions on the characteristics of dense SnO2-based 　
　ceramics, J. Mater. Sci., 38(2003) 2727
2.J.A. Varela, L.A. Perazolli, J.A. Cerri, E.R. Leite, E. Longo, Sintering of
　tin oxide and its applications in electronics and processing of high purity
　optical glasses, Ceramica, 47(2001) 302
3.S.J. Park, K. Hirota, H. Yamamura, Densification of non-additive SnO2 by hot 　isostatic pressing, Ceram. Int., 10(1984) 115
4.E.R. Leite, J.A. Cerri, E. Longo, J.A. Varela, C.A. Paskocima, Sintering of 　ultrafine undoped SnO2 powder. J. Eur. Ceram. Soc., 21(2001) 669
5.W.C. Las, N. Dolet, P. Dordor,J.P. Bonnet, Influence of additives on the 　
　electrical properties of dense SnO2-based ceramics, J. Appl. Phys., 74[10]
　(1993) 6191
6.I.O. Mazali, W.C. Las, M. Cilense, The effect of preparation method and Sb 　
　content on SnO2-CuO sintering, J. Mater. Sci., 38(2003) 3325
7.M. Zaharescu, S. Mihaiu, S. Zuca, K. Matiasovsky, Contribution to the study
　of SnO2-based ceramics Part. I High-temperature interactions of tin(IV)
　oxide with antimony(III) oxide and copper(II) oxide, J. Mater. Sci., 26
　(1991) 1666
8.C.M. Wang, J.F. Wang, H.C. Chen, W.B. Su, G.Z. Zang, P. Qi, M.L. Zhao,
　Effects of CuO on the grain size and electrical properties of SnO2-based
　varistors, Mater. Sci. Eng. B, 116(2005) 54
9.O. Scalat, S. Mihaiu, Gh. Aldica, M. Zaharescu, J. Groza, Enhanced
　Properties of Tin(IV) Oxide Based Materials by Field-Activated Sintering, J.
　Am. Ceram. Soc., 86[6](2003) 893
10.S. Mihaiu, O. Scalat, Gh. Aldica, M. Zaharescu, SnO2 electro- ceramics with
　various additives, J. Eur. Ceram. Soc., 21(2001) 1801
11.M.R. Cassia-Santos, V.C. Sousa, M.M. Oliveira, F.R. Sensato, W.K. Bacelar,
　J.W. Gomes, E. Longo, E.R. Leite, J.A. Varela, Recent research developments
　in SnO2-based varistors, Mater. Chem. Phys., 90(2005) 1
12.O. Scalat, M. Mihaiu, M. Zaharescu, J. Eur. Ceram. Soc., Subsolidus phase
　relations in the SnO2-CuSb2O6 binary system, 22(2002) 1839
13.汪建民, 液相燒結理論及應用, in 粉末冶金, 汪建民、朱秋龍等著,中華民國粉末冶金
　協會 (1991)第8章 165-178
14.W.D. Kingery, B. Francois, Sintering of crystalline oxides. I. Interactions
　between grain boundaries and pores, in Sintering and Related Phenomena, ed.
　G.C. Kuczynski, N.A. Hooton, C.F. Gibbon, Gordon & Breach, (1967) 471-498
15.余樹楨, 晶體內部原子排列－晶體結構, in 晶體之結構與性質, 余樹楨著, 渤海堂,
　(1987)第十二章281-284
16.J.A. Varela, E. Longo, N. Barelli, A.S. Tanaka, W.A. Mariano, Ceramica, 31
　(1985) 241
17.C.L. Hoenig, A.W. Searcy, Knudsen and Langmuir evaporation studies of
　stannic oxide, J. Am. Ceram. Soc., 49(1966) 128
18.J. Lalande, R.O. Fichet, P. Boch, Sintering behaviour of CuO-doped SnO2, J.
　Eur. Ceram. Soc., 20(2000) 2415
19.T. Kikuchi, M. Umehara, Relation between antimony content and lattice
　parameters of Sb-Sn oxide, J. Mater. Sci. Lett., 4(1985) 1051
20.C. Terrier, J.P. Chatelon, R. Berjoan, J.A. Roger, Sb-doped SnO2
　transparent conducting oxide from the sol-gel dip-coating technique, Thin
　Solid Films, 263(1995) 37
21.F.J. Berry, Tin-antimony oxide oxidation catalysts, Hyperfine Interactions,
　111(1998) 35
22.C.D. Wagner, W.M. Riggs, L.E. Davis, J.F. Moulder, G.E. Muilenberg, III.
　Appendix, in Handbook of X-ray Photoelectron Spectroscopy, Perkin-Elmer
　Corporation(1978) 185
23.E. Levin, C.R. Robbins, H.F. McMurdie, Phase Diagrams for Ceramists Vol.II,
　American Ceramic Society Inc. (1964) Fig.2069
24.A.M.M. Gadalla, W.F. Ford, J. White, Equilibrium Relationships in the
　System CuO-Cu2O-SiO2, Trans. Br. Ceram. Soc., 62(1963) 57
25.J.P. Bonnet, N. Dolet, J.M. Heintz, Low-Temperature Sintering of 0.99SnO2-
　0.01CuO: Influence of Copper Surface Diffusion, J. Eur. Ceram. Soc., 16
　(1996) 1163
26.W.D. Kingery, H.K. Bowen, D.R. Uhlmann, Introduction to Ceramics 2nd
　Edition, Wiley-Interscience (1976)Chap.10 446-475, Chap.11 489-495
27.D. Lynn Johnson, A General Model for the Intermediate Stage of Sintering,
　J. Am. Ceram. Soc., 53[10](1970) 574