Optical properties and structure of tellurium–germanium– bismuth–antimony compounds with fast phase-change capability

2001 ◽  
Vol 89 (6) ◽  
pp. 3290-3294 ◽  
Author(s):  
C. M. Lee ◽  
T. S. Chin ◽  
E. Y. Huang
Keyword(s):  
Optical Properties ◽  
Phase Change ◽  
Fast Phase ◽  
Bismuth Antimony

Characterization of Ultra-Fast Phase Change Optical Disk with GaSb Material

2003 ◽  
Vol 803 ◽  
Author(s):  
Kazunori Ito ◽  
Hiroko Tashiro ◽  
Makoto Harigaya ◽  
Eiko Suzuki ◽  
Katsuhiko Tani ◽  
...  
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Melting Point ◽  
Phase Change ◽  
Crystal Growth Rate ◽  
Crystallization Mechanism ◽  
Fast Phase ◽  
Optical Disks ◽  
Digital Versatile Disk

ABSTRACTWe studied the crystallization mechanism of ultra-fast phase change optical disks with recording layers made of GaSb material for digital versatile disk (DVD) systems. The results of a static recording test and an amorphous mark formation simulation suggest that GaSb maintains a high crystal growth rate even at temperatures 150 degrees lower than the material's melting point. Disks with recording layers made of this material have a write speed margin ranging from DVD 3× to 8× or more.

Transparent wood with thermo-reversible optical properties based on phase-change material

2020 ◽  
Vol 200 ◽  
pp. 108407
Author(s):  
Zhe Qiu ◽  
Shuo Wang ◽  
Yonggui Wang ◽  
Jian Li ◽  
Zefang Xiao ◽  
...  
Keyword(s):  
Optical Properties ◽  
Phase Change ◽  
Phase Change Material ◽  
Change Material

scholarly journals Simultaneously high thermal stability and ultra-fast phase change speed based on samarium-doped antimony thin films

RSC Advances ◽  
2017 ◽  
Vol 7 (49) ◽  
pp. 31110-31114 ◽  
Author(s):  
Hua Zou ◽  
Yifeng Hu ◽  
Xiaoqin Zhu ◽  
Zhitang Song
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Phase Change ◽  
High Thermal Stability ◽  
Trade Off ◽  
Fast Phase ◽  
Crystallization Speed

In general, there is trade-off between the crystallization speed and the thermal stability. Here, the Sm–Sb materials simultaneously realize high thermal stability and the ultrafast phase change speed by Sm doping.

Exploring the limits of fast phase change materials

2001 ◽  
Vol 674 ◽  
Author(s):  
Han-Willem Wöltgens ◽  
Ralf Detemple ◽  
Inés Friedrich ◽  
Walter K. Njoroge ◽  
Ingo Thomas ◽  
...  
Keyword(s):  
Activation Energy ◽  
Phase Change ◽  
Phase Change Materials ◽  
Ternary Alloys ◽  
Electrical Measurements ◽  
Material Synthesis ◽  
Fast Phase ◽  
Chalcogenide Alloys ◽  
Speed Up ◽  
Critical Nuclei

ABSTRACTIn the last decade a number of chalcogenide alloys, including ternary alloys of GeSbTe and quaternary alloys of InAgSbTe, have been identified which enable fast phase change recording. In the quest for materials with improved phase change kinetics we present two different approaches. By comparing alloys with well-defined stoichiometries the mechanisms which govern the transformation kinetics are determined. Optical and electrical measurements determine the activation energy for crystallization to 2.24 ± 0.11 eV for Ge2Sb2Te5 and to 3.71 ± 0.07 eV for Ge4Sb1Te5, respectively. It is shown that for GeSbTe-alloys with different composition the activation energy increases linearly with increasing Ge content. Power-time- reflectivity change diagrams recorded with a static tester reveal that Ge2Sb2Te5, in agreement with previous data, recrystallizes by the growth of sub critical nuclei, while Ge4Sb1Te5 grows from the crystalline rim surrounding the bit.To speed up the search for faster materials we employ concepts of combinatorial material synthesis by producing films with a stoichiometry gradient. Then laterally resolved secondary neutral mass spectroscopy (SNMS) combined with the static tester are used to identify the composition with superior properties for phase change applications.

Optical Properties and Phase Transformation Kinetics of Ge-Sb-Te-(N) Alloy Thin Films Investigated by Ellipsometry

2003 ◽  
Vol 803 ◽  
Author(s):  
Sang Youl Kim
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Optical Properties ◽  
Phase Change ◽  
Crystallization Behavior ◽  
Ex Situ ◽  
Recent Analysis ◽  
Avrami Equation ◽  
Step Process ◽  
Kinetics Of

ABSTRACTThe recent research works of optical properties and crystallization kinetics of phase change Ge-Sb-Te-(N) alloy by using ellipsometry are reviewed.The complex refractive index spectra of phase-change Ge2Sb2+xTe5 thin films and those of the nitrogen Ge2Sb2Te5 thin films have been determined.The crystallization behavior of amorphous Ge2Sb2Te5 thin films investigated by in situ ellipsometry revealed that the crystallization process of Ge2Sb2Te5 near 140°C is a two-step process. The kinetic exponent of the Johnson-Mehl-Avrami equation was about 4.4 for the first stage and 1.1 for the second stage. Ex situ study confirmed the cascaded crystallization behavior of phase-change Ge2Sb2Te5 films.A passive type single wavelength ellipsometer adopting a DOAP (division-of-amplitude photopolarimeter) configuration with nanosecond time resolution is developed to monitor the phase transformation of Ge2Sb2Te5 caused by a high power nanosecond laser pulse in real time. The two-step process - the fast nucleation-dominant stage followed by the slow anomalous grain growth stage is confirmed.Based on the recent analysis of the ellipsometric isotherm at moderately elevated temperature, we found for the first time that the fast nucleation dominant crystallization of Ge2Sb2Te 5 can be better explained by a modified JMA equation that illustrates the nucleation dominated process where the creation rate of a new nucleus is proportional to the density of preexisting nuclei and growth rate is negligible.

Optical properties of Ag8In14Sb55Te23 phase-change films

2002 ◽  
Vol 402 (1-2) ◽  
pp. 232-236 ◽  
Author(s):  
Jinyan Li ◽  
Fuxi Gan
Keyword(s):  
Optical Properties ◽  
Phase Change
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