Ultrafast crystalline-to-amorphous phase transition in Ge2Sb2Te5 chalcogenide alloy thin film using single-shot imaging spectroscopy

• Takeda, Jun

• Oba, Wataru

• Minami, Yasuo

• Saiki, Toshiharu

• Katayama, Ikufumi

Abstract

We have observed an irreversible ultrafast crystalline-to-amorphous phase transition in Ge2Sb2Te5chalcogenide alloy thin film using broadband single-shot imaging spectroscopy. The absorbancechange that accompanied the ultrafast amorphization was measured via single-shot detection evenfor laser fluences above the critical value, where a permanent amorphized mark was formed. Theobserved rise time to reach the amorphization was found to be ～130-200 fs, which was in goodagreement with the half period of the A1 phonon frequency in the octahedral GeTe6 structure. Thisresult strongly suggests that the ultrafast amorphization can be attributed to the rearrangement ofGe atoms from an octahedral structure to a tetrahedral structure. Finally, based on the dependenceof the absorbance change on the laser fluence, the stability of the photoinduced amorphous phase isdiscussed. VC 2014 AIP Publishing LLC.

Journal

• Applied physics letters

  Applied physics letters 104 (26), 2014-06-30

Details

• CRID: 1050564287767677312
• NII Article ID: 120005464758
• NII Book ID: AA00543431
• ISSN: 00036951
• Web Site: http://hdl.handle.net/10131/8705
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles