TY - JOUR
KW - paper
AU - W Welnic
AU - JA Kalb
AU - D Wamwangi
AU - C Steimer
AU - Matthias Wuttig
AB - Phase change materials possess a unique combination of properties, which includes a pronounced property contrast between the amorphous and crystalline state, i.e., high electrical and optical contrast. In particular, the latter observation is indicative of a considerable structural difference between the amorphous and crystalline state, which furthermore is characterized by a very high vacancy concentration unknown from common semiconductors. Through the use of ab initio calculations, this work shows how the electric and optical contrast is correlated with structural differences between the crystalline and the amorphous state and how the vacancy concentration controls the optical properties. Furthermore, crystal nucleation rates and crystal growth velocities of various phase change materials have been determined by atomic force microscopy and differential thermal analysis. In particular, the observation of different recrystallization mechanisms upon laser beating of amorphous marks is explained by the relative difference of just three basic parameters among these alloys, namely, the melt-crystalline interfacial energy, the entropy of fusion, and the glass transition temperature.
BT - JOURNAL OF MATERIALS RESEARCH
CY - 506 KEYSTONE DR, WARRENDALE, PA 15086 USA
DA - SEP
DO - 10.1557/JMR.2007.0301
M1 - 9
N2 - Phase change materials possess a unique combination of properties, which includes a pronounced property contrast between the amorphous and crystalline state, i.e., high electrical and optical contrast. In particular, the latter observation is indicative of a considerable structural difference between the amorphous and crystalline state, which furthermore is characterized by a very high vacancy concentration unknown from common semiconductors. Through the use of ab initio calculations, this work shows how the electric and optical contrast is correlated with structural differences between the crystalline and the amorphous state and how the vacancy concentration controls the optical properties. Furthermore, crystal nucleation rates and crystal growth velocities of various phase change materials have been determined by atomic force microscopy and differential thermal analysis. In particular, the observation of different recrystallization mechanisms upon laser beating of amorphous marks is explained by the relative difference of just three basic parameters among these alloys, namely, the melt-crystalline interfacial energy, the entropy of fusion, and the glass transition temperature.
PB - MATERIALS RESEARCH SOCIETY
PP - 506 KEYSTONE DR, WARRENDALE, PA 15086 USA
PY - 2007
SP - 2368
EP - 2375
T2 - JOURNAL OF MATERIALS RESEARCH
TI - Phase change materials: From structures to kinetics
UR - http://dx.doi.org/10.1557/JMR.2007.0301
VL - 22
ER -