title: Influence of the local structure in phase-change materials on their dielectric permittivity.
abstract: Ge-Sb-Te alloys, which belong to the phase-change materials, are promising materials for data storage and display and data visualization applications due to their unique properties. This includes a remarkable difference of their electrical and optical properties in the amorphous and crystalline state. Pronounced change of optical properties for Ge-Sb-Te alloys is linked to the different bonding types and different atomic arrangements in amorphous and crystalline states. The dielectric function of phase-change materials has been investigated in the far infrared (FIR) range. Phonons have been detected by FTIR spectroscopy. Difference of the dispersion of the dielectric permittivity of amorphous and crystalline samples is caused by different structures in different states which contribute to the dielectric permittivity.
authors: I. Institute of Physics (IA), RWTH University of Technology Aachen, Sommerfeldstr. 14, Aachen, 52056 Germany ; Department of semiconductor heterostructures, V.E. Lashkarev Institute for semiconductor physics of NAS of Ukraine, 45 Nauki av, Kyiv, 03028 Ukraine.
authors: Kostiantyn V
authors: KV
authors: Shportko
authors: Department of semiconductor heterostructures, V.E. Lashkarev Institute for semiconductor physics of NAS of Ukraine, 45 Nauki av, Kyiv, 03028 Ukraine.
authors: Eugen F
authors: EF
authors: Venger
keywords: Dielectric function; Phase-change materials; Phonon