Thermal conductivity of phase-change material Ge2Sb 2Te5

Ho Ki Lyeo, David G. Cahill, Bong Sub Lee, John R. Abelson, Min Ho Kwon, Ki Bum Kim, Stephen G. Bishop, Byung Ki Cheong

Research output: Contribution to journalArticlepeer-review


The thermal conductivity of thin films of the phase-change material Ge2 Sb2 Te5 is measured in the temperature range of 27 °C<T<400 °C using time-domain thermoreflectance. From the low thermal conductivity of amorphous phase, the conductivity increases irreversibly with increasing temperature and undergoes large changes with phase transformations. Thermal transport in the amorphous and early cubic phases can be described by a random walk of vibrational energy, i.e., the minimum thermal conductivity. In the hexagonal phase, the electronic contribution to the thermal conductivity is larger than the lattice contribution. Crystallization by laser processing produces a cubic phase with a lower thermal conductivity than cubic phases produced by thermal annealing; the authors attribute this difference in conductivity to a larger degree of atomic-scale disorder in films that are crystallized on short time scales.

Original languageEnglish (US)
Article number151904
JournalApplied Physics Letters
Issue number15
StatePublished - 2006

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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