Second-order Structural Transition in (Ca0.5Sr0.5)3Rh4Sn13

International Conference on Strongly Correlated Electron Systems 2016

Cheung, Y.W.^1 ; Hu, Y.J.^1 ; Goh, S.K.^1 ; Kaneko, K.^2 ; Tsutsui, S.^3 ; Logg, P.W.^4 ; Grosche, F.M.^4 ; Kanagawa, H.^5 ; Tanioku, Y.^5 ; Imai, M.^5 ; Matsumoto, T.^5 ; Yoshimura, K.^5

Department of Physics, Chinese University of Hong Kong, Shatin N.T., Hong Kong^1

Materials Sciences Research Center, Japan Atomic Energy Agency, Naka, Ibaraki, Tokai

319-1195, Japan^2

Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, Sayo, Hyogo

679-5198, Japan^3

Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge

CB3 0HE, United Kingdom^4

Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto

606-8502, Japan^5

关键词: Modulation vectors;    Quantum critical points;    Second orders;    Stoichiometric compound;    Structural transitions;    Superlattice reflections;    Thermal hysteresis;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/807/3/032002/pdf
DOI  :  10.1088/1742-6596/807/3/032002

来源: IOP

【 摘 要 】

(Ca0.5Sr0.5)3Rh4Sn13is a member of the substitution series (CaxSr1-x)3Rh4Sn13which has recently been argued to feature a structural quantum critical point at xc= 0.9. In the stoichiometric compound Sr3Rh4Sn13, the structural transition at T∗ ≈ 138 K has been shown to be second-order. Moving towards xc, we examine the character of the structural transition in (Ca0.5Sr0.5)3Rh4Sn13(i.e. x = 0.5, T∗ ≈ 55 K) using electrical resistivity, heat capacity and X-ray scattering. The absence of the thermal hysteresis in specific heat around T∗, and the continuous evolution of the superlattice reflection detected by X-ray diffraction are consistent with the scenario that the structural transition associated with a modulation vector q = (0.5 0.5 0) in (Ca0.5Sr0.5)3Rh4Sn13remains second-order on approaching the quantum critical point.