Thermal conductivity of GeTe/Sb2Te3 superlattices measured by coherent phonon spectroscopy

被引：14

作者：

Hase, Muneaki ^{[1
]}

Tominaga, Junji ^{[2
]}

机构：

[1] Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 3058573, Japan

[2] Natl Inst Adv Ind Sci & Technol, Nanoelect Res Inst, Tsukuba, Ibaraki 3058562, Japan

来源：

APPLIED PHYSICS LETTERS | 2011年 / 99卷 / 03期

关键词：

PHASE-CHANGE MEMORY; FILMS; SCATTERING;

D O I：

10.1063/1.3611030

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We report on evaluation of lattice thermal conductivity of GeTe/Sb2Te3 superlattice (SL) by using femtosecond coherent phonon spectroscopy at various lattice temperatures. The time-resolved transient reflectivity obtained in amorphous and crystalline GeTe/Sb2Te3 SL films exhibits the coherent A optical modes at terahertz (THz) frequencies with picoseconds dephasing time. Based on the Debye theory, we calculate the lattice thermal conductivity, including scattering by grain boundary and point defect, umklapp process, and phonon resonant scattering. The results indicate that the thermal conductivity in amorphous SL is less temperature dependent, being attributed to dominant phonon-defect scattering. (C) 2011 American Institute of Physics. [doi:10.1063/1.3611030]

引用

页数：3

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