[seminar] Seminar na IF-u, 4. ožujka 2014. u 15:00h

[Niksa Krstulovic]

Institut za fiziku, Bijenička cesta 46, 

predavaonica u zgradi Mladen Paić utorak, 4. ožujka 2014., u 15:00 sati 

Ferroelectricity in water ice films on Pt(111) 





Yoshiyasu Matsumoto 

Graduate School of Science, Department of Chemistry, Kyoto University, Japan 

E-mail: matsumoto at kuchem.kyoto-u.ac.jp 



Water crystalline ice has a tetrahedral arrangement of hydrogen bonding. In this arrangement, there are still many possible ways to configure protons, i.e., the orientations of water dipole. If water dipoles are arranged such that a net orientation toward one direction is left, the water ice becomes ferroelectric. However, the ferroelectric bulk ice is elusive because of slow kinetics from paraelectric ice. Therefore, catalzying the orientational flipping is necessary by doping ions in ice [1]. 



Using the interaction of water with substrate where ice films are grown is another way to realize ferroelectricity of ice. Shen's group has demonstrated using sum-frequency generation (SFG) spectroscopy that ferroelectric ice films can be grown on Pt(111) and the surface-induced proton ordering decays with 30 monolayers of water [2]. In contrast, Cowin's group has revealed using a Kelvin probe that partial proton oders sustain over many layers and give no indication of reaching any limit [3]. Thus, although these studies clealy demonstrate that the interaction of water with substrate is a key to grow ferroelectric ice films, the length scales of partial ordering are very different and this conflict has not been solved yet. 



Recently we investigated the ferroelectricity of crystalline and amorphous ice 
films on Pt(111) using SFG with homodyne and heterodyne detections together with temperature-programmed desorption (TPD). Heterodyne detection of SFG allows us to determine the orientation of water molecules in the films. Simultaneous measurements of homodyne SFG intensities and TPD provide the temperature dependence of the order parameter. Here, I present very recent results and discuss about the conflict cited above, the orientation of water molecules, and the transition between ferro- and paraelectric states in the 
films. 



References 

[1] Y. Tajima, T. Matsuo, and H. Suga. Phase transition in koh-doped hexagonal ice, Nature, 299:810-812 1982. 

[2] X. Su, L. Lianos, Y. R. Shen, and G. A. Somorjai, Surface-induced ferroelectric ice on Pt(111), Phys. Rev. Lett., 80:1533 1998. [3] M. J. Iedema, M. J. Dresser, D. L. Doering, J. B. Rowland, W. P. Hess, A. A. Tsekouras, and J. P. Cowin, Ferroelectricity in water ice, J. Phys. Chem. B, 102:9203-9214 1998. 

http://www.kuchem.kyoto-u.ac.jp/organization/member/matsumoto_e.html 





Voditelji seminara IF-a: Nikša Krstulović i Osor Bari šić 
************************* 
Nikša Krstulović, PhD 
Research associate 

Institute of Physics 
Bijenicka 46 
HR-10000 Zagreb, Croatia 

Phone: 00385 1 4698 872 
00385 1 4698 851 
Fax: 00385 1 4698 889 

http://www.ifs.hr/ 
http://spectra.ifs.hr/ 
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