複合鈣鈦礦結構材料具有高Q值的特性，近年來已成為發展高頻濾波器的主要研究目標。在此系列中，如Ba(Mg1/3Ta2/3)O3（BMT）具有極高的Q值，廣泛地被應用於通訊元件中。但要獲得其優良的介電性質，必須在高溫及長時間的燒結條件下才能獲得，主要原因在於必須克服鋇/鉭原子本身低的燒結性。

在本論文研究第一部份，即利用固相反應法去合成Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 (BMNxT4-x)陶瓷，研究鈮原子取代Ba(Mg1/3Ta2/3)O3陶瓷中之鉭原子位置對其燒結性質、微結構以及微波介電性質之影響，且進一步利用高解析穿透式電子顯微鏡(HRTEM)分析其有序結構，找出利用摻雜取代方式對Ba(Mg1/3Ta2/3)O3複合鈣鈦礦陶瓷對其有序結構以及介電損失(Qf值)之影響。

在本論文研究之第二部分即是研究添加不同含量燒結添加劑(CuO和B2O3)於Ba[Mg1/3(Nb1/4Ta3/4)2/3]O3 (BMN1T3)陶瓷中，研究其燒結行為、微結構以及微波介電性質之影響，找出最佳燒結添加劑的添加量，且進一步利用高解析穿透式電子顯微鏡(HRTEM)分析其有序結構，研究找出其燒結添加劑對其有序結構以及介電損失(Qf值)之主要影響機制。

在Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 (BMNxT4-x)陶瓷中，由於鈮和鉭原子有相近的離子半徑，所以在各種鈮原子取代量下之BMNT陶瓷都能形成良好的固溶體且都維持其1：2有序化結構。在有1：2有序化結構之晶粒中，利用TEM分析可觀察到代表反相區塊晶界(antiphase domain boundary APB)的弧狀條紋存在。

在BMNT陶瓷中，在鈮原子取代量為x = 1時之BMN1T3陶瓷經1650℃燒結9小時，可獲得一最佳之微波介電性質：介電常數εr為25.53 ，Qf值為140,666 GHz及共振頻率溫度係數τf值為4.8 ppm/℃。在BMNT陶瓷中，其介電常數與共振頻率溫度係數隨著鈮原子取代量增加而提高，主要是因為鈮原子完全取代鉭原子形成完美固溶體所造成之結果。在BMN1T3陶瓷中，在APB位置上一額外新有序結構([111]方向之晶格調變為1.24 nm)形成且與相鄰兩1：2有序結構間形成原子耦合度佳之界面，有效提高界面穩定性並減少介電損失的來源，因而大幅提高其Qf值。

添加0.5 wt%氧化銅於BMN1T3陶瓷，在1525℃燒結9小時即可獲得燒結緻密(相對密度96%)之試片，且仍具有絕佳之微波介電性質：介電常數εr為24.5，，Qf值為100,000 GHz。氧化銅助燒結劑與BMN1T3陶瓷之主要成分在晶界形成另一低熔點化合物，利用液相燒結方式幫助燒結已降低BMN1T3陶瓷之燒結溫度。

添加1.0 wt%氧化硼於BMN1T3陶瓷，在1400℃燒結9小時即可獲得一燒結緻密(相對密度98%)之試片，且仍具有絕佳之微波介電性質：介電常數εr為25.2，，Qf值為88,678 GHz。氧化硼助燒結劑在BMN1T3陶瓷燒結過程中，藉由形成非結晶玻璃相，利用液相燒結方式有效降低BMN1T3陶瓷所需之燒結溫度。

在添加氧化銅或氧化硼助燒結劑於BMN1T3陶瓷研究中可知，其微波介電性質主要與其燒結密度與微結構有關；而在APB位置上無序結構的產生，則是在較低溫度燒結所獲得緻密試片，其Qf值也微幅降低之主要原因。

A complex perovskite ceramic A(B1/3B’2/3)O3, is known to be excellent for the dielectric resonator and is used widely. One of the most important factors for improving the unloaded Q of the perovskite A(B1/3B’2/3)O3 ceramics is the ordering of B site in A(B1/3B’2/3)O3. Although this material has excellent microwave dielectric properties, the high sintering temperature (1600- 1650oC) and long soaking time(～50 hours) due to low sinterability of Ba and Ta atoms is a problem.

In this research including two main parts:
(1) Investigation of sintering behavior and high-frequency microwave properties in Ba(Mg1/3Ta2/3)O3（BMT）with B atomic site replaced by Nb atom.

Ba[Mg1/3（Nbx/4Ta(4-x)/4）2/3]O3 （x = 0, 1,2, 3,和4） microwave dielectric ceramics were synthesized by solid state reactive method. The influences of Nb atom substitution in Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 ceramic were investigated in respect of sintering behavior, microstructure, ordering degree and microwave dielectric properties by using density measurement, SEM, XRD, TEM and cavity method. Furthermore, the high resolution transmission electron microscope (HRTEM) was used to elucidate the relationship between the long-rang ordered structure and dielectric loss in the Ba[Mg1/3（Nbx/4Ta(4-x)/4）2/3]O3 ceramic with various Nb substitution contents.

(2) Investigation of sintering behavior and high-frequency microwave properties in Ba[Mg1/3（Nbx/4Ta(4-x)/4）2/3]O3（BMNT）with various sintering additives

Different kinds (copper oxide and boron oxide) and various contents of sintering additives were added to the Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 (BMN1T3) ceramics. The influences of sintering additives in Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 ceramic were investigated in respect of sintering behavior, microstructure, ordering degree and microwave dielectric properties by density measurement, SEM, XRD, TEM and cavity method. Furthermore, the high resolution transmission electron microscope (HRTEM) was used to elucidate the relationship between the long-rang ordered structure and dielectric loss in the Ba[Mg1/3（Nbx/4Ta(4-x)/4）2/3]O3 ceramic with carious Nb substitution contents.

In the Ba[Mg1/3(Nbx/4Ta(4-x)/4)2/3]O3 (BMNxT4-x) ceramics, it was suggested that the BMNT ceramics with various Nb substitution contents could be formed as a good solid solution and maintain the 1：2 ordering structure due to the similar ionic radius between the Nb and Ta atoms. The antiphase domain boundary (APB) which shows the curved fringe in the TEM micrograph could be observed in the BMNT grain with the 1：2 ordering structure.

The BMN1T3 ceramic (Nb substitution content x =1 ) was sintered at 1650℃ for 9 hours and could obtain a excellent microwave dielectric properties: dielectric constant εr = 25.53 , Qf = 140,666 GHz and the temperature coefficient of resonant frequency τf = 4.8 ppm/℃.In the BMNT ceramics, the increase of εr and τf with the Nb substitution content was due to the formation of solid solution. In the BMN1T3 ceramic, the lowest dielectric loss was contributed to the formation of a extra ordered structure (lattice modulation in the [111] direction is 1.24 nm) on the APB. The extra ordered structure has a coherent interface with the adjacent 1：2 ordering structure so effectively improve the stability of domain boundary and decrease the dielectric loss.

The BMN1T3 ceramic with 0.5 wt% CuO which was sintered at 1525℃ for 9 hours could have a good sintering density (relative density 96%) and maintain the good microwave dielectric properties: εr = 24.5, Qf = 100,000 GHz. The CuO additive formed a compound with the BMN1T3 ceramic and effectively lowers the sintering temperature of the BMN1T3 ceramic by liquid phase sintering.

The BMN1T3 ceramic with 1.0 wt% B2O3 which was sintered at 1400℃ for 9 hours could have a good sintering density (relative density 98%) and maintain the good microwave dielectric properties: εr = 25.2, Qf = 88,678 GHz. In the sintering process of the BMN1T3 ceramic, the B2O3 additive forms a amorphous glass and effectively lowers the sintering temperature of the BMN1T3 ceramic by liquid phase sintering.

In the BMN1T3 ceramic with the sintering additive, it was suggested that the microwave dielectric properties were primarily influenced by the sintering density and microstructure. The formation of disordered structure on the APB was contributed to the lower Qf value of the dense specimen sintered at lower temperature.

[1] R. D. Richtmyer, “Dielectric Resonator”, J. Appl. Phys., 10, pp. 391-398 (1939)
[2] S. B. Cohn, “Microwave Bandpass Filters Containing High-Q Dielectric Resonator”, IEEE Trans. On MIT, MIT-16, pp.217-218 (1968)
[3] S. Kawashima, M. Nishida, I. Ueda, and H. Ouchi, ‘‘Ba(Zn1/3Ta2/3)O3 Ceramics with Low Dielectric Loss at Microwave Frequencies, ’’ J. Am. Ceram. Soc., 66 [6] 421–23 (1983)
[4] K. Matsumoto, T. Hiuga, K. Takada, and H. Ichimura, ‘‘Ba(Mg1/3Ta2/3)O3 Ceramics with Ultra-Low Loss at Microwave Frequencies’’; pp. 118–21 in Proceedings of the 6th IEEE International Symposium on Application of Ferroelectrics (June 1986). Institute of Electrical and Electronic Engineers, New York, 1986.
[5] S. B. Desu and H. M. O’Bryan, ‘‘Microwave Loss Quality of BaZn0.33Ta0.67O3 Ceramics,’’ J. Am. Ceram. Soc., 68 [10] 546–51 (1985).
[6] T. Shimada. “Dielectric loss and damping constants of lattice vibrations in Ba(Mg1/3Ta2/3)O3 ceramics” Journal of the European Ceramic Society 23 (2003) 2647–2651
[7] H. Tamura, T. Konoike, Y. Sakabe, and K. Wakino, ‘‘Improved High Q Dielectric Resonator with Complex Perovskite Structure,’’ J. Am. Ceram. Soc.,67 [4] C-59–C-61 (1984).
[8] Hwack Joo Lee,† Hyun Min Park, Yang Koo Cho, and Hyun R. “Dielectric and Structural Characteristics in Barium Lanthanum Magnesium Niobate” J. Am. Ceram. Soc., 83 [4] 937–42 (2000)
[9] Hwack Joo Lee,† Hyun Min Park, and Hyun Ryu. “Microstructural Changes in Lanthanum-Doped Barium Magnesium Niobate” J. Am. Ceram. Soc., 82 [9] 2529–37 (1999)
[10] Lai-Cheng Tien, Chen-Chia Chou and Dah-Shyang Tsai. “Ordered Structure and Dielectric Properties of Lanthanum-Substituted Ba(Mg1/3Ta2/3)O3” J. Am. Ceram. Soc., 83 [8] 2074–78 (2000)
[11] Jung-In Yang, Sahn Nahm_, Seok-Jin Yoon, Hyun-Min Park and Hwack-Joo Lee ” Structural Variation and Microwave Dielectric Properties of ZrO2 Added Ba(Zn1/3Ta2/3)O3 Ceramics” Jpn. J. Appl. Phys. Vol. 43, No. 1, 2004, pp. 211–214
[12] Cheol-Woo Ahn, Sahn Nahm_, Seok-Jin Yoon, Hyun-Min Park and Hwack-Joo Lee “Microstructure and Microwave Dielectric Properties of (1-x)Ba(Co1/3Nb2/3)O3–xBa(Zn1/3Nb2/3)O3 Ceramics” Jpn. J. Appl. Phys. Vol. 42 (2003) pp. 6964–6968
[13] Cheng-Liang Huang, Kuo-Hau Chiang, She-Cher Chuang. “Influence of V2O5 additions to Ba(Mg1/3Ta2/3)O3 ceramics on sintering behavior and microwave dielectric properties” Materials Research Bulletin 39 (2004) 629–636
[14] Jong-Bong Lim, Jin-ok Son, Sahn Nahm, Woo-Sung Lee, Myong-Jae Yoo, Nam-Gi Gang, Hwack-Joo Lee and Young-Sik Kim. “Low-Temperature Sintering of B2O3-Added Ba(Mg1/3Nb2/3)O3 Ceramics” Jpn. J. Appl. Phys. Vol. 43, No. 8A, 2004, pp. 5388–5391
[15] Jong-Bong Lim, Dong-Hyun Kim, Sahn Nahm,Jong-Hoo Paikb, Hwack-Joo Lee. “Effect of B2O3 and CuO additives on the sintering temperature and microwave dielectric properties of Ba(Mg1/3Nb2/3)O3 ceramics” Materials Research Bulletin 41 (2006) 1199–1205
[16] Min-Han Kim, Young-Hun Jeong , Sahn Nahm, Hyo-Tae Kim, Hwack-Joo Lee. “Effect of B2O3 and CuO additives on the sintering temperature and microwave dielectric properties of Ba(Zn1/3Nb2/3)O3 ceramics” Journal of the European Ceramic Society Vol. 26 (2006) p.2139-2142.
[17] W. H. Sutton, “Microwave Process of Ceramics- An overview”, Mater. Res. Soc. Symp.Proc., C269., p3-20(1992)
[18] J. M. Osepchuk, “A History of Microwave Heating Applications”, IEEE Trans. on Microwave Theory and Tech.”, Mtt-32 p1200-1224(1984)
[19] E. Hund, “Microwave Communications – Components and Circuits”, McGraw- Hill Chap. 2 (1989)
[20] D.Kajfez “Computed Model Field Distribution for Isolated Dielectric Resonators” IEEE.Trans.MTT, vol.MTT-32, p1609-1616,1984
[21] D.Kajfez “Basic Principle Give Understanding of Dielectric Wave-guides and Resonators” Microwave System News,vol.13,p.152-161,1983
[22] D.Kajfez and P.Guillon “Drelectric Resonators” ,1989
[23] W.J.Huppmann and G.Petzow “The Elementary Mechanisms of Liquid Sintering” ,Sintering Processes,Plenum Press,p.189-202,1979
[24] W.D. Kingery, H. K. Bowen, D. R. Uhlman, “Introduction to Ceramics” Cha. 18 (1975)
[25] D. M. Pozar, “Microwave Engineering” J. Appl. Phys. Vol. 10, p191(1939)
[26] B. W. Hakki and P. D. Coleman, “A Dielectric Resonator Method of Measuring Inductive Capacities in Millimeter Range” IRE Tran. On Microwave Theory and Tech., p402-410 (1960)
[27] Y. Kobayashi and S. Tanaka, “Resonant Modes of a Dielectric Rod Resonator Short – Circuited at Both Ends by Parallel Conducting Plates” IEEE Transaction on Microwave Theory and Tech.”, V, MTT-28[10], p1077-1085(1980)
[28] Y. Kobayashi and M. Katohy, “Microwave Measurement of Dielectric Properties of Low-Loss Materials by the Dielectric Rod Resonator Method”, IEEE Trans. on Microwave Theory and Tech., V. MTT-33, NO.7, p586-592(1985).
[29] K. Wakino et al., ”Precise Measurement Method for High Frequency Dielectric” IEEE. Proc. 8th, IASF, p3-8(1995)
[30] Y. Kobayashi et al., “Influence of Conductor shields on the Q-Factors of a TE0nl Dielectric Resonator” IEEE Transaction on Microwave Theory and Tech.”V. MTT-33[12], p131-1366(1985)
[31] D. Kajfez, “ Incremental Frequency Rule for Computing the Q-factor of shielded TE0mp Dielectric Resonator” IEEE Transaction on Microwave Theory and Tech.”V. MTT-32, No.8(1984)
[32] R. C. Kell, A. C. Greenham and G. C. E. Olds “High-Permittivity Temperature-Stable Ceramics Dielectric with low Microwave Loss”, J. Am. Ceram. Soc., Vol. 56, pp.352-354 (1973)
[33] T. Yamaguchi et al., “Newly Developed Ternary (Ca,Sr,Ba) Zirconate Ceramic System for Microwave Resonators”, Ferroelectrics, Vol.27, pp.273-276(1980)
[34] H. M. O’Bryan et al., “Phase Equilibrium in the TiO2-Rich Region of the system BaO-TiO2”, J. Am. Ceram. Soc., Vol.57[12], pp.522-526(1974)
[35] H. M. O’Bryan et al., ”A New BaO-TiO2 Compound with Temperature-Stable High Permittivity and Low Microwave Loss”, J. Am. Ceram. Soc., Vol.57[10], pp.450-453(1974)
[36] P. C. Osbond et al., “The Properties and Microwave Applications of Zircinnium Titanate Stannate Ceramics” Brit. Ceram. Proc., Vol.36, pp.167-178.(1985)
[37] K. Wakino and H. Tamura, “Microwave Characteristics of (Zr,Sn)TiO4 and BaO-PbO-Nd2O3-TiO2 Dielectric Resonators”, J. Am. Ceram. Soc., Vol.67, pp.278-281(1984)
[38] B. D. Cullity and S. R. Stock “Elements of X-Ray Diffraction” 2nd edited, Chap. 13, p.383-395.
[39] W.J.Huppmann and G.Petzow “The Elementary Mechanisms of Liquid Sintering” ,Sintering Processes, Plenum Press, p.189-202,1979
[40] W.E.Courtney “Analysis and evaluation of a method of measuring the complex permittivity and permeability of microwave insulators” IEEE. Trans. Microwave Theory Tegh. ,vol.MTT-18,p.476-485,1970
[41] P. Wheless and D.Kajfez"The Use of Higher Resonant Modes in Measuring the Dielectric Constant of Dielectric Resonators” IEEE
[42] Seung-Hyun Ra and Pradeep P. Phulé “Processing and microwave dielectric properties of barium magnesium tantalite ceramics for high-quality-factor personal communication service filter,” J. Mater. Res., Vol. 14, No. 11, p4259-65.
[43] X. Hu, X, M. and YJ. Wu, “Nd-substituted Ba(Mg1/3Ta2/3)O3 microwave dielectric ceramics,” Material Letter, 54, p279-83 (2002).
[44] K. Matsumoto, T. Hiuga, K. Takada and H. Ichinura, “Ba(Mg1/3Ta2/3)O3 ceramics with ultra-low loss at microwave frequencies.” Proc. 6th IEEE Inter. Sym. Applications of Ferroelectrics, The American Ceramic Society, 1986, p.118–121
[45] A. Dias, V. S. T. Ciminelli, F. M. Matinaga and R. L. Moreira: Raman scattering and X-ray diffraction investigations on hydrothermal barium magnesium Niobate ceramics. J. Eur. Ceram. Soc., 21, 2739 (2001).
[46] T. Kolodiazhnyi, A. Petric, A. Belous, O. V’yunov and O. Yanchevskij, ”Synthesis and dielectric properties of barium tantalates and niobates with complex perovskite structure,” J. Mater. Res., Vol. 17, No. 12, p3182-89.
[47] B. D. Cullity and S.R. Stock, Chapter 4, Elements of X-ray Diffraction, Prentice Hall, Inc. New Jersey.
[48] H. Hughes, D. M. Iddies and I. M. Reaney, “Niobate-based microwave dielectrics suitable for third generation mobile phone base station,” Applied Physics Letter Vol. 79, No.18, p2952-2954.
[49] T.V. Kolodiazhnyia, A. Petrica,, G.P. Joharia and A.G. Belousb, “Effect of preparation conditions on cation ordering and dielectric properties of Ba(Mg1/3Ta2/3)O3 ceramics,” J. Eur. Ceram. Soc., 22, p2013-21. (2002).
[50] Hill, N. E., Vaughan, W. E., Price, A. H. and Davies, M.,” Dielectric properties and molecular behavior,” Van Nostrand Reinhold Company, London, p. 283. (1969).
[51] Ki Hyun Yoon, Dong Pil Kim, and Eung Soo Kim. “Effect of BaWO4 on the microwave dielectric properties of Ba(Mg1/3Ta2/3)O3 ceramics,” J. Am. Ceram. Soc., 77[4] p.1062-66 (1994).
[52] Mehmet A. Akbas and Peter K. Davies, “Ordering-induced microstructures and microwave dielectric properties of the Ba(Mg1/3Nb2/3)O3–BaZrO3 system,” J. Am. Ceram. Soc., 81[3] p.670-76 (1998).
[53] Lai-Cheng Tien, Chen-Chia Chou and Dah- Shyang Tsai, ”Microstructure of Ba(Mg1/3Ta2/3)O3 – BaSnO3 microwave dielectrics,” Ceramics International 26 p.57-62. (2000).

[54] F. Galasso and J. Pyle, “Ordering in Compounds of the A(B’0.33Ta0.67)O3 Type,” Inorg. Chem., 2, p.482–84 (1963).
[55] D. J. Barber, K. M. Moulding, Ji Zhou and Maoqiang Li, “Structural order in Ba(Zn1/3Ta2/3)O3, Ba(Zn1/3Nb2/3)O3 and Ba(Mg1/3Ta2/3)O3 microwave dielectric ceramics,” Journal of Materials Science, 32, p1531-44, (1997).
[56] Hwack Joo Lee, Hyun Min Park, Yang Koo Cho, Hyun Ryu, Yong Won Song Jong Hoo Paik, Sahn Nahm, and Jae-Dong Byun, “Microstructural observations in barium calcium magnesium niobate,” J. Am. Ceram. Soc., 83[9] p.2267-72,(1997).
[57] Young-Woong Kim, Jae-Hwan Park and Jae-Gwan Park: Local cationic ordering behavior in Ba(Mg1/3Nb2/3)O3 ceramics. J. Eur. Ceram. Soc. 24, 17757(2004).
[58] Peter K. Davies, Jianzhu Tong and Taki Negas: Effect of ordering-induced domain boundaries on low-loss Ba(Zn1/3Ta2/3)O3–BaZrO3 perovskite microwave dielectrics, J. Am. Ceram. Soc., 80, 1727 (1997).
[59] V. Satheesh, P. Murugavel, V. R. K. Murthy, and B. Viswanathan, “Synthesis and role of Nd and Sm on the microwave dielectric properties of BaNd2(1-x)Sm2xTi5O14 dielectric resonator,” Materials Science and Engineering, B48, p.202-04. (1997).
[60] Lai-Cheng Tien, Chen-Chia Chou and Dah-Shyang Tsai, “Ordered structure and dielectric properties of lanthanum-substituted Ba(Mg1/3Ta2/3)O3,” J. Am. Ceram. Soc., 83[8] p.2074-78,(2000).
[61] Hwack Joo Lee, Hyun Min Park, Yang Koo Cho, Hyun Ryu, Jong Hoo Paik, Sahn Nahm, and Jae-Dong Byun: Dielectric and structural characteristics in barium lanthanum magnesium niobate. J. Am. Ceram. Soc., 83, 937 (2000).
[62] Hwack Joo Lee, Hyun Min Park, Hyun Ryu, Jong Hoo Paik, Sahn Nahm, and Jae-Dong Byun: Microstructural changes in lanthanum-doped barium magnesium niobate. J. Am. Ceram. Soc., 82, 2529 (1999).
[63] J. Sun, Shaojun Liu, N. Newman and David J. Smith: Ordered domains and boundary structure in Ba(Cd1/3Ta2/3)O3 perovskite dielectrics. Appl. Phys. Lett., 84, 3918 (2004).
[64] J. Sun, Shaojun Liu, M. R. McCartney and David J. Smith: Electron microscopy characterization of Ba(Cd1/3Ta2/3)O3 microwave dielectrics with boron additive. J. Mater. Res. Vol.19, NO. 5, P1387-1391.
[65] Shaojun Liu, J. Sun, Richard Taylor, David J. Smith and N. Newman: Microstructure and dielectric properties of Ba(Cd1/3Ta2/3)O3 microwave ceramics synthesized with a boron oxide sintering aid. J. Mater. Res. Vol.19, NO. 12, P.3526-3533.
[66] W. Wersing : High frequency ceramic dielectrics and their application for microwave components: Electronic ceramic, edited by B. C. H. Steele (Elsevier Applied Science, London, 1991). P.67.

[67] Dong-Wan Kim, Kyung Hyun Ko and Kug Sun Hong: Influence of Copper oxide addtions to zinc niobate microwave ceramics on sintering temperature and dielectric properries. J. Am. Ceram. Soc., 84[6] , P.1286-90(2001)

[68] Cheng-Shing Hsu, Cheng-Liang Huang, Jing-Fang Tseng and Chi-Yuen Huang: Improveed high-Q microwave dielectric resonator using CuO-doped MgNb2O6 ceramics. Materials Research Bulletin 38(2003), P.1091-1099.
[69] C. J. Lee, G. Pezzotti, Shin H. Kang, Deug J. Kim and Kug Sun Hong: Quantitative analysis of lattice distortion in Ba(Zn1/3Ta2/3)O3 microwave dielectric ceramics with added B2O3 using Raman spectroscopy. J. Eur. Ceram. Soc. Vol. 26, Issue 8, P.1385-1391(2006)