Anomalous Pressure Dependence of the Superconducting Transition   Temperature in TlNi$_2$Se$_{2-x}$S$_x$
  We report the pressure dependence of the superconducting transition temperature, $T_c$, in TlNi$_2$Se$_{2-x}$S$_x$ detected via the AC susceptibility method. The pressure-temperature phase diagram constructed for TlNi$_{2}$Se$_{2}$, TlNi$_{2}$S$_{2}$ and TlNi$_{2}$SeS exhibits two unexpected features: (a) a sudden collapse of the superconducting state at moderate pressure for all three compositions and (b) a dome-shaped pressure dependence of $T_c$ for TlNi$_{2}$SeS. These results point to the nontrivial role of S substitution and its subtle interplay with applied pressure, as well as novel superconducting properties of the TlNi$_2$Se$_{2-x}$S$_x$ system. 
S. K. Goh, H. C. Chang, P. Reiss, P. L. Alireza, Y. W. Cheung, S. Y.   Lau, Hangdong Wang, Qianhui Mao, Jinhu Yang, Minghu F...
cond-mat.supr-con cond-mat.str-el