Pressure Induced Superconductivity in Ba0.5Sr0.5Fe2As2
  High-pressure electrical resistance measurements have been performed on single crystal Ba0.5Sr0.5Fe2As2 platelets to pressures of 16 GPa and temperatures down to 10 K using designer diamond anvils under quasi-hydrostatic conditions with an insulating steatite pressure medium. The resistance measurements show evidence of pressure-induced superconductivity with an onset transition temperature at ~31 K and zero resistance at ~22 K for a pressure of 3.3 GPa. The transition temperature decreases gradually with increasing in pressure before completely disappearing for pressures above 12 GPa. The present results provide experimental evidence that a solid solution of two 122-type materials, e.g., Ba1-x.SrxFe2As2 (0 < x <1), can also exhibit superconductivity under high pressure 
Georgiy M. Tsoi, Walter Malone, Walter Uhoya, Jonathan E. Mitchel,   Yogesh K. Vohra, Lowell E. Wenger, Athena S. Sefat, and...
cond-mat.supr-con cond-mat.mtrl-sci cond-mat.other