ナビゲーション


Local structure analysis of rewritable optical media during phase change

  • Only SPring-8

Body text

In this solution, EXAFS method was applied to Ge2Sb2Te5 thin film (20 nm thickness), the material of rewritable optical media, to analyze local structural change during phase change. EXAFS spectra of the sample in crystalline and amorphous phase were measured at Ge, Sb and Te K-edge. The EXAFS method is a powerful technique to study local structure (distance, coordination number, species of neighbor atoms) of selected elements both in crystalline states and in non-crystalline states. Figure 1 shows radial structure function of Te atom after Fourier transform of EXAFS spectra. Simultaneous analysis of EXAFS data set at 3 edges revealed that the fast rewritable mechanism is due to the change in position of Ge atom in rigid building blocks.

Fig. 1 Radial structure function for Te atom in crystallized and amorphized samples.

Fig. 2 Fragments of the local structure of GST around Ge atoms in the crystalline (left)
and amorphous (right) states (red: Ga).

[ A. V. Kolobov, P. Fons, A. I. Frenkel, A. L. Ankudinov, J. Tominaga, T. Uruga, Nature Materials 3, 703-708 (2004), Fig. 1(c), 5,
©2004 Nature Publishing Group ]

Scientific keywords

A. Sample category inorganic material
B. Sample category (detail) metal, alloy, semiconductor, solid-state crystal, amorphous, glass, inorganic thin film
C. Technique absorption and its secondary process
D. Technique (detail) XAFS, EXAFS, XANES
E. Particular condition polarization (linear), room temperature
F. Photon energy X-ray (4-40 keV)
G. Target information chemical bonding, local structure, structural change, function and structure, function, phase transition

Industrial keywords

level 1---Application area storage device
level 2---Target CD-R、DVD
level 3---Target (detail)
level 4---Obtainable information structure of non-crystalline material, interatomic distance, crystal structure, local structure, electronic state
level 5---Technique XAFS

Inquiry number

SOL-0000001053

Last modified 2008-03-11 18:32
カレンダー