Prospective

In recent years, there are many theoretical studies and many experimental reports on physical properties dramatically influenced by various effects, such as substitution, shape, size, strain, etc. The continuous advance in miniaturization of devices, fine structure as a ferric material have been applied in advanced electric devices such as ferroelectric random access memory (FRAM), multilayer ceramic capacitor (MLCC), and in other integrated devices. Among these effects, the size dependence of properties with different shapes is presently one of the major research topics.

It is necessary for us to synthesize various high purity perovskite nanocrystals with uniform size and homogeneous shape. BaTiO3 nanoparticles with uniform size were synthesized by glycothermal treatment and size-dependent properties were

discussed. Furthermore, much effort has been recently put into morphology controlled synthesis of crystalline ferroelectric oxide materials because the effects of a large nonlinear optical coefficient and a large dielectric constant are highly dependent on the size and shape. [1] Of various nanostructures low-dimensional nanostructures, such as nanoparticles, nano-wires, nanocubes and nanorods, have especially received great interest from the scientific and engineering communities [2, 3] because these structures exhibit distinct physical and chemical properties from bulk materials due to their smaller particle sizes and larger surface-to-volume ratios. Thus, many studies have probed the optical, [4] electronic, [5] and magnetic [6] properties of these nanostructures. Scientists expect one-dimensional (1D) structures, nano-rods, and nanowires to provide new alternatives for developing devices because of recent theoretical studies from the first principles and experiments on ferroelectric nanowires.

This possibility primarily arises because the size-dependent ferroelectricity of 1D structures functions with much smaller diameters than do 0-D structures (nanoparticle), and the Curie temperature is reduced as the diameter of the 1D structure is reduced. [7-9] Wang et al. [10] also reported a method for studying the axial poling and switching in 1D BaTiO3 nanowires by using piezoresponse force microscopy (PFM).

Therefore, we have proposed the novel insight into the nature of low-dimensional ABO3 nanostructures related to the size and shape experimentally and theoretically. Because the ABO3 1D nanostructure is difficult to obtain due to the isotropy of the ABO3 crystal structure and the anisotropy of the 1D structure, the control of nucleation and growth of 1D nanostructure materials is still a big challenge.

Presently, the three-series products (BT-1, spherical BaTiO3; BT-2, cube-shaped BaTiO3; and BT-3, rod-shaped BaTiO3) were synthesized roughly with different barium and multishaped titanium precursors. (see Figure 8.1)

  Figure 8.1: SEM images of the three-series products: BT-1, BT-2, and BT-3.

Magnetoelectric (ME) effect in multiferroics is an important mechanism in applications of transducers, actuators, and sensors. The ME coupling in bi-ferroic (e.g., PbTiO3-CoFe2O4) self-assembled epitaxial nanostructures occurs indirectly via the elastic coupling. Although theoretical studies [11-13] point out the importance of the residual strains in the ME coupling, there is limited information on the lattice strains in ferromagnetic nanostructures in a ferroelectric matrix. We also reported on the relationship between local behavior of interfacial phonons and ferromagnetic properties in bi-ferroic (PbTiO3-CoFe2O4). Their energy of interfacial phonons and ferromagnetic properties depend on stress due to not only the lattice misfit but also the degree of chemical bonding at the interface between matrices. At the same time, we still hope a detailed study of lattice strains for bi-ferroic nanocomposite heteroepitaxial structure could be continued experimentally and theoretically in the future based on the accomplishment have been done in this thesis.

References

[1] S. O’Brien, L. Brus, and C. B. Murray, J. Am. Chem. Soc. 123,12085 (2001).

[2] A. P. Alivisatos, Science 271, 933 (1996).

[3] J. T. Hu, T. W. Odom, and C. M. Lieber, Acc. Chem. Res. 32, 435 (1999).

[4] M. H. Huang, S. Mao, H. Feick, H. Q. Yan, Y. Y. Wu, H. Kind, E. Weber, R.

Russo, and P. D. Yang, Science 292, 1897 (2001).

[5] T. Thurn-Albrecht, J. Schotter, C. A. Kastle, N. Emley, T. Shibauchi, L.

Krusin-Elbaum, K. Guarini, C. T. Black, M. T. Tuominen, and T. P. Russell, Science 290, 2126 (2000).

[6] W. J. Liang, M. Bockrath, D. Bozovic, J. H. Hafner, M. Tinkham, and H. Park, Nature, 411, 665 (2001).

[7] G. Geneste, E. Bousquet, J. Junquera, P. Ghosez, Appl. Phys. Lett. 88, 3 (2006).

[8] J. W. Hong and D. N. Fang, Appl. Phys. Lett. 92, 3 (2008).

[9] J. E. Spanier, A. M. Kolpak, J. J. Urban, I. Grinberg, O. Y. Lian, W. S. Yun, A.

M. Rappe, and H. Park, Nano Lett. 6, 735 (2006).

[10] Z. Y. Wang, A. P. Suryavanshi, and M. F. Yu, Appl. Phys. Lett. 89, 3 (2006).

[11] J. Slutsker, Z. Tan, A. L. Roytburd, and I. Levin, J. Mater. Res. 22, 2087 (2007).

[12] C. G. Zhong, Q. Jiang, J. Fang, and X. F. Jiang, J. Appl. Phys. 105,044901 (2009).

[13] G. Liu, C. W. Nan, and J. Sun, Acta Mater. 54, 917 (2006).

黃同慶簡歷 (Vita)

基本資料

姓名：黃 同 慶 (Tung-Ching Huang) 性別：男

出生年月日： 1973 年 10 月 25 日 籍貫: 台南縣

永久通訊處：(722)台南縣佳里鎮興化里8鄰佳里興479 號之3

email:[email protected]; [email protected]

學歷：

1993.8 – 1998.7 國立台灣師範大學物理系 學士 2001.8 – 2003.7 國立交通大學光電所 碩士 2003.8 – 2009.10 國立交通大學光電所 博士

經歷：

1998.8 – 2001.7 臺北市立重慶國中理化教師

博士論文題目 :

鈣鈦礦結構對螢光及鐵性材料特性的影響

Influence of perovskite structure on luminescence and

characteristics of ferroics

Publication list

I. Refereed Journal Publications:

1 Tung-Ching Huang, Mei-Tan Wang, Hwo-Shuenn Sheu, and Wen-Feng Hsieh,

“Size-dependent lattice dynamics of barium titanate nanoparticles”, Journal of Physics-Condensed Matter, 19, 476212 (2007).

2 Tung-Ching Huang and Wen-Feng Hsieh, “Er-Yb Codoped Ferroelectrics for Controlling Visible Upconversion Emissions”, Journal of Fluorescence, 19, 511 (2009).

3 Tung-Ching Huang and Wen-Feng Hsieh, “Destruction of the short-range disorder due to erbium doping in Pb0.8La0.2TiO3 films”, Journal of Raman Spectroscopy, accepted for publication (2009).

4 Kuan-Chih Huang, Tung-Ching Huang, and Wen-Feng Hsieh,

“Morphology-Controlled Synthesis of Barium Titanate Nanostructures”, Inorganic Chemistry, 48(19):9180-4 (2009).

II. Conference:

1. Tung-Ching Huang and Wen-Feng Hsieh, “Decreasing Splitting of LO-TO Phonons in BaTiO3 Nanoparticles Due to Unit-cell Volume”, in 2006 MRS Spring Meeting, San Francisco, USA, post paper (2006).

2. Tung-Ching Huang and Wen-Feng Hsieh, “Quenching green and enhancing red upconversion emissions of Er³⁺ by reducing tetragonality in Yb³⁺ co-doped ferroelectrics”, 2008 E-MRS Fall Meeting, Warsaw, Poland, oral paper (2008).

3. Tung-Ching Huang and Wen-Feng Hsieh, “Destruction to the short-range disorder due to erbium dopant in Pb0.8La0.2TiO3 poly-crystalline films”, in

Conference of Year 2005 Annual Meeting of Chinese Physical Society, Kaoshiung, TAIWAN, oral paper (2005).

4. Mei-Tan Wang, Tung-Ching Huang, and Wen-Feng Hsieh, “Grain size effect on the lattice dynamics of barium titanate nanoparticles” in Conference of Year 2007 Annual Meeting of Chinese Physical Society, Chunli, TAIWAN, oral paper (2007) 5. Tung-Ching Huang,Chung-Ting Li, Shou-Yi Kuo, and Wen-Feng Hsieh, in

Proceedings of Optics and Photonics Taiwan'02, Taipei, TAIWAN, post paper (2002)