High-pressure studies of superconductivity in $$\hbox {BiO}_0.75\hbox {F}_0.25\hbox {BiS}₂$$ BiO 0.75 F 0.25 BiS 2

(hbox {BiO}_0.75hbox {F}_0.25hbox {BiS}₂) crystallizes in tetragonal CeOBiS(₂) structure (S. G. P4/nmm). We have investigated the effect of pressure on magnetization measurements. Our studies suggest improved superconducting properties in polycrystalline samples of (hbox {BiO}_0.75hbox {F}_0.25hbox {BiS}₂). The (T_{mathrm{c}}) in our sample is 5.3 K, at ambient pressure, which is marginal but definite enhancement over (T_{mathrm{c}}) reported earlier (= 5.1 K). The upper critical field (H_{mathrm{c}2})(0) is greater than 3 T, which is higher than earlier report on this material. As determined from the M–H curve, both (H_{mathrm{c}2}) and (H_{mathrm{c}1}) decrease under external pressure P (0 (le P le ) 1 GPa). We observe a decrease in critical current density and transition temperature on applying pressure in (hbox {BiO}_0.75hbox {F}_0.25hbox {BiS}₂).