Review of Sintering Technologies, Structural Characteristics, and Piezoelectric Properties of NKN-Based Lead-Free Ceramics

  • Tae-Gon Lee
  • Sahn NahmEmail author
Review Paper


The (Na1−xKx)NbO3-based (NKN-based) lead-free piezoelectric ceramics have been extensively investigated from the beginning of this century to replace the Pb(Zr1−xTix)O3-based piezoelectric ceramics. The sintering of the NKN-based ceramics is difficult because they are soluble in water, and Na2O evaporation, which degrades the piezoelectric properties of the specimen, occurs during sintering. CuO was used as a sintering aid to improve the sinterability and to reduce the sintering temperature of the NKN ceramics. The NKN-based ceramics with various polymorphic phase boundary (PPB) structures such as orthorhombic–tetragonal PPB, rhombohedral–orthorhombic PPB, and rhombohedral–tetragonal PPB structures were developed to enhance the piezoelectric properties. The specimen with the rhombohedral–tetragonal PPB structure has been reported to show excellent piezoelectric properties. Recently, NKN-based ceramics with various pseudocubic-based PPB structures were reported, and they exhibited enhanced piezoelectric properties with good thermal stability. In this manuscript, the sintering of NKN-based ceramics and the various PPB structures developed for improving their piezoelectric properties are discussed in detail.


Lead free ceramic NKN ceramic Low temperature sintering Phase transition Polymorphic phase boundary structure Piezoelectric property 



  1. 1.
    J.G. Yi, S. Chang, Y.T. Shen, IEEE-ASME Trans. Mechatron. 14, 456 (2009)CrossRefGoogle Scholar
  2. 2.
    M.S. Senousy, R.K.N.D. Rajapakse, D. Mumford, M.S. Gadala, Smart Mater. Struct. 18, 045008 (2009)CrossRefGoogle Scholar
  3. 3.
    J.P. Li, X.Q. Zhou, H.W. Zhao, M.K. Shao, N. Li, S.Z. Zhang, Y.M. Du, IEEE-ASME Trans. Mechatron. 22, 541 (2017)CrossRefGoogle Scholar
  4. 4.
    Y. Lu, H. Tang, S. Fung, Q. Wang, J.M. Tsai, M. Daneman, B.E. Boser, D.A. Horsley, Appl. Phys. Lett. 106, 263503 (2015)CrossRefGoogle Scholar
  5. 5.
    K.R. Kumar, S. Narayanan, Smart Mater. Struct. 17, 055008 (2008)CrossRefGoogle Scholar
  6. 6.
    M.J. Johnson, D.R. Boris, T.B. Petrova, S.G. Walton, IEEE Trans. Plasma Sci. 47, 434 (2019)CrossRefGoogle Scholar
  7. 7.
    Z. Ramshani, M.J. Johnson, M.Z. Atashbar, D.B. Go, Appl. Phys. Lett. 109, 044103 (2016)CrossRefGoogle Scholar
  8. 8.
    H.C. Xiong, L.B. Wang, Appl. Energy 174, 101 (2016)CrossRefGoogle Scholar
  9. 9.
  10. 10.
    Y. Seo, D. Corona, N.A. Hall, Sens. Actuators A-Phys. 264, 341 (2017)CrossRefGoogle Scholar
  11. 11.
    T. Ibn-Mohammed, S.C.L. Koh, I.M. Reaney, A. Acquaye, D. Wang, S. Taylor, A. Genovese, Energy Environ. Sci. 9, 3495 (2016)CrossRefGoogle Scholar
  12. 12.
    E. Ringgaard, T. Wurlitzer, J. Eur. Ceram. Soc. 25, 2701 (2005)CrossRefGoogle Scholar
  13. 13.
    S.H. Park, C.W. Ahn, S. Nahm, J.S. Song, Jpn. J. Appl. Phys. 2(43), L1072 (2004)CrossRefGoogle Scholar
  14. 14.
    A.J. Bell, O. Deubzer, MRS Bull. 43, 581 (2018)CrossRefGoogle Scholar
  15. 15.
    P.K. Panda, B. Sahoo, Ferroelectrics 474, 128 (2015)CrossRefGoogle Scholar
  16. 16.
    J. Koruza, A.J. Bell, T. Frömling, K.G. Webber, K. Wang, J. Rödel, J. Materiomics 4, 13 (2018)CrossRefGoogle Scholar
  17. 17.
    H.G. Wei, H. Wang, Y.J. Xia, D.P. Cui, Y.P. Shi, M.Y. Dong, C.T. Liu, T. Ding, J.X. Zhang, Y. Ma, N. Wang, Z.C. Wang, Y. Sun, R.B. Wei, Z.H. Guo, J. Mater. Chem. C 6, 12446 (2018)CrossRefGoogle Scholar
  18. 18.
    M.X. Zhou, R.H. Liang, Z.Y. Zhou, S.G. Yan, X.L. Dong, ACS Sustain. Chem. Eng. 6, 12755 (2018)CrossRefGoogle Scholar
  19. 19.
    W.F. Liu, X.B. Ren, Phys. Rev. Lett. 103, 257602 (2009)CrossRefGoogle Scholar
  20. 20.
    Y.R. Cui, X.Y. Liu, M.H. Jiang, X.Y. Zhao, X. Shan, W.H. Li, C.L. Yuan, C.R. Zhou, Ceram. Int. 38, 4761 (2012)CrossRefGoogle Scholar
  21. 21.
    X.M. Chen, X.Z. Ruan, K.Y. Zhao, X.Q. He, J.T. Zeng, Y.S. Li, L.Y. Zheng, C.H. Park, G.R. Li, J. Alloys Compd. 632, 103 (2015)CrossRefGoogle Scholar
  22. 22.
    X.L. Chao, J.J. Wang, P.F. Liang, T. Zhang, L.L. Wei, Z.P. Yang, Mater. Des. 89, 465 (2016)CrossRefGoogle Scholar
  23. 23.
    X. Liu, Z.H. Chen, B.J. Fang, J.N. Ding, X.Y. Zhao, H.Q. Xu, H.S. Luo, J. Alloys Compd. 640, 128 (2015)CrossRefGoogle Scholar
  24. 24.
    J.G. Hao, W.F. Bai, W. Li, J.W. Zhai, J. Am. Ceram. Soc. 95, 1998 (2012)CrossRefGoogle Scholar
  25. 25.
    W. Jo, R. Dittmer, M. Acosta, J.D. Zang, C. Groh, E. Sapper, K. Wang, J. Rodel, J. Electroceram. 29, 71 (2012)CrossRefGoogle Scholar
  26. 26.
    K.N. Pham, A. Hussain, C.W. Ahn, I.W. Kim, S.J. Jeong, J.S. Lee, Mater. Lett. 64, 2219 (2010)CrossRefGoogle Scholar
  27. 27.
    W.F. Bai, P. Li, L.Y. Li, J.J. Zhang, B. Shen, J.W. Zhai, J. Alloys Compd. 649, 772 (2015)CrossRefGoogle Scholar
  28. 28.
    L.L. Li, J.G. Hao, Z.J. Xu, W. Li, R.Q. Chu, Mater. Lett. 184, 152 (2016)CrossRefGoogle Scholar
  29. 29.
    P. Li, B.H. Liu, B. Shen, J.W. Zhai, L.Y. Li, H.R. Zeng, Ceram. Int. 43, 1008 (2017)CrossRefGoogle Scholar
  30. 30.
    C. Wang, X.J. Lou, T.D. Xia, S.T. Tian, Ceram. Int. 43, 9253 (2017)CrossRefGoogle Scholar
  31. 31.
    A. Hussain, C.W. Ahn, J.S. Lee, A. Ullah, I.W. Kim, Sens. Actuators A-Phys. 158, 84 (2010)CrossRefGoogle Scholar
  32. 32.
    R.A. Malik, J.K. Kang, A. Hussain, C.W. Ahn, H.S. Han, J.S. Lee, Appl. Phys. Express 7, 061502 (2014)CrossRefGoogle Scholar
  33. 33.
    J.U. Rahman, A. Hussain, A. Maqbool, G.H. Ryu, T.K. Song, W.J. Kim, M.H. Kim, J. Alloys Compd. 593, 97 (2014)CrossRefGoogle Scholar
  34. 34.
    F.F. Wang, M. Xu, Y.X. Tang, T. Wang, W.Z. Shi, C.M. Leung, J. Am. Ceram. Soc. 95, 1955 (2012)CrossRefGoogle Scholar
  35. 35.
    H.B. Lee, D.J. Heo, R.A. Malik, C.H. Yoon, H.S. Han, J.S. Lee, Ceram. Int. 39, S705 (2013)CrossRefGoogle Scholar
  36. 36.
    W.F. Bai, D.Q. Chen, Y.W. Huang, P. Zheng, J.S. Zhong, M.Y. Ding, Y.J. Yuan, B. Shen, J.W. Zhai, Z.G. Ji, Ceram. Int. 42, 7669 (2016)CrossRefGoogle Scholar
  37. 37.
    A. Hussain, J.U. Rahman, A. Zaman, R.A. Malik, J.S. Kim, T.K. Song, W.J. Kim, M.H. Kim, Mater. Chem. Phys. 143, 1282 (2014)CrossRefGoogle Scholar
  38. 38.
    E.A. Patterson, D.P. Cann, J. Pokorny, I.M. Reaney, J. Appl. Phys. 111, 094105 (2012)CrossRefGoogle Scholar
  39. 39.
    R.A. Malik, A. Hussain, J.U. Rahman, A. Maqbool, T.K. Song, W.J. Kim, S.Y. Ryou, M.H. Kim, Mater. Lett. 143, 148 (2015)CrossRefGoogle Scholar
  40. 40.
    H.B. Zhang, C. Groh, Q. Zhang, W. Jo, K.G. Webber, J. Roedel, Adv. Electron. Mater. 1, 1500018 (2015)CrossRefGoogle Scholar
  41. 41.
    J.H. Kim, D.H. Kim, I.T. Seo, J. Hur, J.H. Lee, B.Y. Kim, S. Nahm, Sens. Actuators A-Phys. 234, 9 (2015)CrossRefGoogle Scholar
  42. 42.
    J.H. Kim, D.H. Kim, T.H. Lee, T.G. Lee, J.H. Lee, B.Y. Kim, S. Nahm, C.Y. Kang, J. Ryu, J. Am. Ceram. Soc. 99, 4031 (2016)CrossRefGoogle Scholar
  43. 43.
    J.H. Lee, D.H. Kim, I.T. Seo, J.H. Kim, J.S. Park, J. Ryu, S.H. Han, B.Y. Jang, S. Nahm, J. Am. Ceram. Soc. 99, 938 (2016)CrossRefGoogle Scholar
  44. 44.
    L. Wang, Z.Y. Zhou, X.B. Zhao, Z. Liu, R.H. Liang, X.L. Dong, Appl. Phys. Lett. 110, 102904 (2017)CrossRefGoogle Scholar
  45. 45.
    Y.J. Dai, Y.J. Zhao, Z. Zhao, Z.H. Zhao, Q.W. Zhou, X.W. Zhang, J. Phys. D Appl. Phys. 49, 275303 (2016)CrossRefGoogle Scholar
  46. 46.
    Z.Y. Feng, X.B. Ren, Appl. Phys. Lett. 91, 032904 (2007)CrossRefGoogle Scholar
  47. 47.
    M. Suzuki, H. Nagata, J. Ohara, H. Funakubo, T. Takenaka, Jpn. J. Appl. Phys. 1(42), 6090 (2003)CrossRefGoogle Scholar
  48. 48.
    H. Nagata, Y. Hiruma, M. Suzuki, T. Takenaka, Electron. Commun. Jpn. 91, 39 (2008)CrossRefGoogle Scholar
  49. 49.
    C.M. Wang, S.J. Zhang, J.F. Wang, M.L. Zhao, C.L. Wang, Mater. Chem. Phys. 118, 21 (2009)CrossRefGoogle Scholar
  50. 50.
    H. Nagata, M. Itagaki, T. Takenaka, Ferroelectrics 286, 807 (2003)CrossRefGoogle Scholar
  51. 51.
    C.M. Wang, J.F. Wang, Z.G. Gai, Scr. Mater. 57, 789 (2007)CrossRefGoogle Scholar
  52. 52.
    C.M. Wang, J.F. Wang, S.J. Zhang, T.R. Shrout, J. Appl. Phys. 105, 094110 (2009)CrossRefGoogle Scholar
  53. 53.
    R. Aoyagi, H. Takeda, S. Okamura, T. Shiosaki, Mater. Sci. Eng. B-Solid 116, 156 (2005)CrossRefGoogle Scholar
  54. 54.
    B.T. Matthias, J.P. Remeika, Phys. Rev. 82, 727 (1951)CrossRefGoogle Scholar
  55. 55.
    G. Shirane, R. Newnham, R. Pepinsky, Phys. Rev. 96, 581 (1954)CrossRefGoogle Scholar
  56. 56.
    L. Egerton, D.M. Dillon, J. Am. Ceram. Soc. 47, 482 (1959)Google Scholar
  57. 57.
    R.H. Dungan, R.D. Golding, J. Am. Ceram. Soc. 48, 601 (1965)CrossRefGoogle Scholar
  58. 58.
    B. Jaffe, Piezoelectric Ceramics (Elsevier, Amsterdam, 2012), pp. 193–194Google Scholar
  59. 59.
    M. Ahtee, A.M. Glazer, Acta Crystallogr. A 32, 434 (1976)CrossRefGoogle Scholar
  60. 60.
    M. Ahtee, A.M. Glazer, Ferroelectrics 7, 93 (1974)CrossRefGoogle Scholar
  61. 61.
    L. Wu, J.L. Zhang, C.L. Wang, J.C. Li, J. Appl. Phys. 103, 084116 (2008)CrossRefGoogle Scholar
  62. 62.
    R.Z. Zuo, J. Rodel, R.Z. Chen, L.T. Li, J. Am. Ceram. Soc. 89, 2010 (2006)CrossRefGoogle Scholar
  63. 63.
    Q. Zhang, B.P. Zhang, H.T. Li, P.P. Shang, Rare Met. 29, 220 (2010)CrossRefGoogle Scholar
  64. 64.
    J. Bernard, A. Bencan, T. Rojac, J. Holc, B. Malic, M. Kosec, J. Am. Ceram. Soc. 91, 2409 (2008)CrossRefGoogle Scholar
  65. 65.
    Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, M. Nakamura, Nature 432, 84 (2004)CrossRefGoogle Scholar
  66. 66.
    I.T. Seo, H.Y. Park, N. Van Dung, M.K. Choi, S. Nahm, H.G. Lee, B.H. Choi, IEEE Trans. Ultrason. Ferroelectr. 56, 2337 (2009)CrossRefGoogle Scholar
  67. 67.
    H.Y. Park, C.W. Ahn, H.C. Song, J.H. Lee, S. Nahm, K. Uchino, H.G. Lee, H.J. Lee, Appl. Phys. Lett. 89, 062906 (2006)CrossRefGoogle Scholar
  68. 68.
    S. Sasikumar, R. Saravanan, J. Electron. Mater. 46, 4187 (2017)CrossRefGoogle Scholar
  69. 69.
    Y.P. Guo, K. Kakimoto, H. Ohsato, Solid State Commun. 129, 279 (2004)CrossRefGoogle Scholar
  70. 70.
    C.W. Ahn, H.C. Song, S. Nahm, S.H. Park, K. Uchino, S. Priya, H.G. Lee, N.K. Kang, Jpn. J. Appl. Phys. 44, L1361 (2005)CrossRefGoogle Scholar
  71. 71.
    G.Z. Zang, J.F. Wang, H.C. Chen, W.B. Su, C.M. Wang, P. Qi, B.Q. Ming, J. Du, L.M. Zheng, Appl. Phys. Lett. 88, 212908 (2006)CrossRefGoogle Scholar
  72. 72.
    H.C. Song, K.H. Cho, H.Y. Park, C.W. Ahn, S. Nahm, K. Uchino, S.H. Park, J. Am. Ceram. Soc. 90, 1812 (2007)CrossRefGoogle Scholar
  73. 73.
    H.Y. Park, K.H. Cho, D.S. Paik, S. Nahm, H.G. Lee, D.H. Kim, J. Appl. Phys. 102, 124101 (2007)CrossRefGoogle Scholar
  74. 74.
    N. Klein, E. Hollenstein, D. Damjanovic, H.J. Trodahl, N. Setter, M. Kuball, J. Appl. Phys. 102, 014112 (2007)CrossRefGoogle Scholar
  75. 75.
    J.G. Wu, D.Q. Xiao, Y.Y. Wang, J.G. Zhu, L. Wu, Y.H. Jiang, Appl. Phys. Lett. 91, 252907 (2007)CrossRefGoogle Scholar
  76. 76.
    R.Z. Zuo, X.S. Fang, C. Ye, L.T. Li, J. Am. Ceram. Soc. 90, 2424 (2007)CrossRefGoogle Scholar
  77. 77.
    C.W. Ahn, C.H. Choi, H.Y. Park, S. Nahm, S. Priya, J. Mater. Sci. 43, 6784 (2008)CrossRefGoogle Scholar
  78. 78.
    J.L. Zhang, X.J. Zong, L. Wu, Y. Gao, P. Zheng, S.F. Shao, Appl. Phys. Lett. 95, 022909 (2009)CrossRefGoogle Scholar
  79. 79.
    L.M. Jiang, Z. Tan, L.X. Xie, Y.Y. Li, J. Xing, J.G. Wu, Q. Chen, D.Q. Xiao, J.G. Zhu, J. Eur. Ceram. Soc. 38, 2335 (2018)CrossRefGoogle Scholar
  80. 80.
    R.Z. Zuo, C. Ye, X.S. Fang, Jpn. J. Appl. Phys. 46, 6733 (2007)CrossRefGoogle Scholar
  81. 81.
    R.P. Wang, H. Bando, T. Katsumata, Y. Inaguma, H. Taniguchi, M. Itoh, Phys. Status Solidi-R 3, 142 (2009)CrossRefGoogle Scholar
  82. 82.
    R.Z. Zuo, J.A. Fu, D.Y. Lv, Y. Liu, J. Am. Ceram. Soc. 93, 2783 (2010)CrossRefGoogle Scholar
  83. 83.
    W.F. Liang, W.J. Wu, D.Q. Xiao, J.G. Zhu, J. Am. Ceram. Soc. 94, 4317 (2011)CrossRefGoogle Scholar
  84. 84.
    J.G. Wu, H. Tao, Y. Yuan, X. Lv, X.J. Wang, X.J. Lou, RSC Adv. 5, 14575 (2015)CrossRefGoogle Scholar
  85. 85.
    R.Z. Zuo, J. Fu, J. Am. Ceram. Soc. 94, 1467 (2011)CrossRefGoogle Scholar
  86. 86.
    B.Y. Zhang, J.G. Wu, X.J. Cheng, X.P. Wang, D.Q. Xiao, J.G. Zhu, X.J. Wang, X.J. Lou, ACS Appl. Mater. Interfaces 5, 7718 (2013)CrossRefGoogle Scholar
  87. 87.
    J. Zushi, T. Ariizumi, S. Kojima, R.P. Wang, H. Bando, Jpn. J. Appl. Phys. 52, 07HB02 (2013)CrossRefGoogle Scholar
  88. 88.
    X.P. Wang, J.G. Wu, D.Q. Xiao, X.J. Cheng, T. Zheng, X.J. Lou, B.Y. Zhang, J.G. Zhu, ACS Appl. Mater. Interfaces 6, 6177 (2014)CrossRefGoogle Scholar
  89. 89.
    T. Zheng, J.G. Wu, X.J. Cheng, X.P. Wang, B.Y. Zhang, D.Q. Xiao, J.G. Zhu, X.J. Loub, X.J. Wang, Dalton Trans. 43, 11759 (2014)CrossRefGoogle Scholar
  90. 90.
    X.P. Wang, J.G. Wu, D.Q. Xiao, J.G. Zhu, X.J. Cheng, T. Zheng, B.Y. Zhang, X.J. Lou, X.J. Wang, J. Am. Chem. Soc. 136, 2905 (2014)CrossRefGoogle Scholar
  91. 91.
    B. Wu, H.J. Wu, J.G. Wu, D.Q. Xiao, J.G. Zhu, S.J. Pennycook, J. Am. Chem. Soc. 138, 15459 (2016)CrossRefGoogle Scholar
  92. 92.
    J. Xing, Z. Tan, L.M. Jiang, Q. Chen, J.G. Wu, W. Zhang, D.Q. Xiao, J.G. Zhu, J. Appl. Phys. 119, 034101 (2016)CrossRefGoogle Scholar
  93. 93.
    K. Xu, J. Li, X. Lv, J.G. Wu, X.X. Zhang, D.Q. Xiao, J.G. Zhu, Adv. Mater. 28, 8519 (2016)CrossRefGoogle Scholar
  94. 94.
    T. Zheng, H.J. Wu, Y. Yuan, X. Lv, Q. Li, T.L. Men, C. Zhao, D.Q. Xiao, J.G. Wu, K. Wang, J.F. Li, Y.L. Gu, J. Zhu, S.J. Pennycook, Energy Environ. Sci. 10, 528 (2017)CrossRefGoogle Scholar
  95. 95.
    K.T. Lee, D.H. Kim, J.S. Park, T.G. Lee, S.H. Cho, S.J. Park, J.Y. Kang, S. Nahm, J. Am. Ceram. Soc. 100, 4827 (2017)CrossRefGoogle Scholar
  96. 96.
    K.T. Lee, D.H. Kim, S.H. Cho, J.S. Kim, J. Ryu, C.W. Ahn, T.H. Lee, G.H. Kim, S. Nahm, J. Alloys Compd. 784, 1334 (2019)CrossRefGoogle Scholar
  97. 97.
    D.H. Kim, T.G. Lee, S.H. Cho, K.T. Lee, T.H. Lee, Y.W. Hong, C.H. Hong, J.S. Kim, S. Nahm, J. Am. Ceram. Soc. 101, 3997 (2018)CrossRefGoogle Scholar
  98. 98.
    T.G. Lee, S.H. Cho, D.H. Kim, H.G. Hwang, K.T. Lee, C.H. Hong, Y.W. Hong, K.H. Chae, J.W. Choi, J.S. Kim, S. Nahm, J. Eur. Ceram. Soc. 39, 973 (2019)CrossRefGoogle Scholar
  99. 99.
    K.T. Lee, T.G. Lee, S.W. Kim, S.J. Chae, E.J. Kim, J.S. Kim, J.W. Choi, S. Nahm, J. Am. Ceram. Soc. (2019). CrossRefGoogle Scholar
  100. 100.
    H.Y. Park, J.Y. Choi, M.K. Choi, K.H. Cho, S. Nahm, H.G. Lee, H.W. Kang, J. Am. Ceram. Soc. 91, 2374 (2008)CrossRefGoogle Scholar
  101. 101.
    S.J. Park, H.Y. Park, K.H. Cho, S. Nahm, H.G. Lee, D.H. Kim, B.H. Choi, Mater. Res. Bull. 43, 3580 (2008)CrossRefGoogle Scholar
  102. 102.
    H.Y. Park, C.W. Ahn, K.H. Cho, S. Nahm, H.G. Lee, H.W. Kang, D.H. Kim, K.S. Park, J. Am. Ceram. Soc. 90, 4066 (2007)Google Scholar
  103. 103.
    I.T. Seo, K.H. Cho, H.Y. Park, S.J. Park, M.K. Choi, S. Nahm, H.G. Lee, H.W. Kang, H.J. Lee, J. Am. Ceram. Soc. 91, 3955 (2008)CrossRefGoogle Scholar
  104. 104.
    I.Y. Kang, I.T. Seo, Y.J. Cha, J.H. Choi, S. Nahm, T.H. Sung, J.H. Paik, J. Eur. Ceram. Soc. 32, 2381 (2012)CrossRefGoogle Scholar
  105. 105.
    X.M. Pang, J.H. Qiu, K.J. Zhu, J.Z. Du, J. Mater. Sci-Mater. Electron. 23, 1083 (2012)CrossRefGoogle Scholar
  106. 106.
    J. Fu, R.Z. Zuo, H. Qi, C. Zhang, J.F. Li, L.T. Li, Appl. Phys. Lett. 105, 242903 (2014)CrossRefGoogle Scholar
  107. 107.
    T.G. Lee, H.J. Lee, D.H. Kim, H. Xu, S.J. Park, J.S. Park, S. Nahm, C.Y. Kang, S.J. Yoon, J. Eur. Ceram. Soc. 36, 4049 (2016)CrossRefGoogle Scholar

Copyright information

© The Korean Institute of Electrical and Electronic Material Engineers 2019

Authors and Affiliations

  1. 1.Department of Nano Bio Information Technology, KU-KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoulRepublic of Korea
  2. 2.Department of Materials Science and EngineeringKorea UniversitySeoulRepublic of Korea

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