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

Y W Cheung, Y J Hu, S K Goh, K Kaneko, S Tsutsui, P W Logg, F M Grosche, H Kanagawa, Y Tanioku, M Imai, T Matsumoto, K Yoshimura
2017 Journal of Physics, Conference Series  
Ca0.5Sr0.5)3Rh4Sn13 is a member of the substitution series (CaxSr1−x)3Rh4Sn13 which 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
more » ... e 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)3Rh4Sn13 remains second-order on approaching the quantum critical point.
doi:10.1088/1742-6596/807/3/032002 fatcat:gymjmmr5wzep5hubd6peyjkoha