The authors synthesised YbRh_xSn_y and CaRh_xSn_y by use of molten-metal-solution growth. It turned out that for the Yb compound two different phases were obtained, depending on the starting composition of the melt. The superconducting phase Yb₃Rh₄Sn₁₃ was quenched from different high temperatures. They found an Arrhenius behaviour of the degradation of the superconducting transition temperature as a function of the quenching temperature. This behaviour is similar to V₃Ga which we measured before. This degradation is ascribed to anti-site disorder in the A15 frame of the ternary crystal structure. Similar results were obtained for the ternary compound Ca₃Rh₄Sn₁₃. The disordering energy turned out to be the same for both ternary stannides (about 1.16 eV). This illustrates the similarity between Ca and divalent Yb.