The local order of amorphous Ge 2 Sb 2 Te 5 films (50 nm) prepared by sputtering (AD), melt quenching (MQ), or ion irradiation (II) has been probed by EXAFS and Raman spectroscopy. The Ge K edge of the AD sample shows a stronger contribution from homopolar Ge-Ge bonds with respect to irradiated films. Raman spectroscopy measurements indicate a greater abundance of homopolar Te-Te bonds in AD film with respect to MQ and II. Irradiation of deposited amorphous GST films results in a reduction of" wrong" homopolar bonds. This variation is probably the origin of the faster crystallization speed of MQ and II amorphous samples.
26 Oct 2011
Volume: 14 Issue: 12 Pages: H480
Electrochemical and Solid State Letters