Interplay between low-energy optical phonon modes and structural transition in PrT2Zn20 (T=Ru and Ir)

International Conference on Strongly Correlated Electron Systems 2014

Wakiya, K.^1 ; Onimaru, T.^1 ; Tsutsui, S.^2,3 ; Matsumoto, K.T.^1 ; Nagasawa, N.^1 ; Baron, A.Q.R.^2,4 ; Hasegawa, T.^5 ; Ogita, N.^5 ; Udagawa, M.^3,5 ; Takabatake, T.^1,3

Department of Quantum Matter, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima

739-8530, Japan^1

Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo

679-5198, Japan^2

Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima

739-8530, Japan^3

Materials Dynamics Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo

679-5148, Japan^4

Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima

739-8521, Japan^5

关键词: Atomic dynamics;    First-principles calculation;    Inelastic x-ray scattering;    Isostructural;    Low energy optical phonon modes;    Low-energy vibrations;    Optical phonons;    Structural transitions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012024/pdf
DOI  :  10.1088/1742-6596/592/1/012024

来源: IOP

【 摘 要 】

Atomic dynamics of PrT2Zn20for T=Ru with a structural transition at Ts=138 K and T=Ir without such a transition have been studied by inelastic X-ray scattering (IXS) measurements. The IXS spectra for T=Ru reveal an optical phonon excitation at 3 meV. We assign it to low-energy vibration of the Zn atom at the 16c site by taking account of the first principles calculation [Hasegawa et al. 2012 J. Phys.: Conf. Proc. 391 012016]. For T=Ir, on the other hand, the optical excitation at 3 meV was not observed. The contrasting results indicate that the low-energy optical phonon mode has a role in the structural transition in PrRu2Zn20and isostructural La counterparts.