The potassium and lanthanum co-doped superconducting series with composition Ba_1-xLa_x/4K_3x/4(Bi_0.25Pb_0.75)O_3-δ where (0.00 ≤ x ≤ 0.40) has been synthesized by solid state reaction. Their crystal structure and superconducting properties has been investigated in detail. All the synthesized samples crystallize in P1 space group as confirmed by the X-ray diffraction analysis. All the samples show sharp superconductivity transitions as confirmed from electrical resistivity measurements. Significantly the $T_c^{onset}$ (the highest temperature at which the electrical resistivity decreases abruptly) ranges from 11.4 to 11.8 K and $T_c^{zero}$ (the highest temperature at which the electrical resistivity becomes zero) ranges from 10.7 to 11.2 K.

通过固相反应合成了成分为Ba _1-x La _x/4 K _3x/4 (Bi _0.25 Pb _0.75 )O _{3- δ}其中(0.00≤x≤0.40)的钾镧共掺杂超导系列。已经详细研究了它们的晶体结构和超导特性。X射线衍射分析证实，所有合成样品均在P 1 空间群中结晶。正如电阻率测量所证实的，所有样品都显示出急剧的超导转变。显着地${吨}_C^{○nse吨}$（电阻率突然降低的最高温度）范围从 11.4 到 11.8 K 和${吨}_C^{zer○}$（电阻率变为零的最高温度）范围为 10.7 至 11.2 K。