Campi D, Bernasconi M, Benedek G, Graham A P, Toennies J P
Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, 20125 Milano, Italy.
Phys Chem Chem Phys. 2017 Jun 28;19(25):16358-16364. doi: 10.1039/c7cp01572k.
The phonon dispersion curves of ultrathin films of Cs(110) on Pt(111) measured with inelastic helium atom scattering (HAS) are reported and compared with density-functional perturbation theory (DFPT) calculations. The combined HAS and DFPT analysis also sheds light on the bulk phonon dynamics of bcc-Cs, on which very little is known from neutron scattering due to its large neutron capture cross-section. Moreover the temperature dependence of the elastic HAS Debye-Waller exponent of Cs(110)/Cu(111) ultrathin films allows for an estimation of the electron-phonon coupling strength λ as a function of the film thickness.
报道了用非弹性氦原子散射（HAS）测量的Pt(111)上Cs(110)超薄膜的声子色散曲线，并与密度泛函微扰理论（DFPT）计算结果进行了比较。HAS和DFPT的联合分析也揭示了体心立方Cs的体声子动力学，由于其较大的中子俘获截面，从中子散射中了解到的相关信息非常少。此外，Cs(110)/Cu(111)超薄膜弹性HAS德拜-瓦勒指数的温度依赖性使得能够估计电子-声子耦合强度λ随薄膜厚度的变化。
