We develop a two-step synthesis method—ultrasound treatment and low temperature annealing to explore superconductivity in potassium-doped triphenylbismuth, which is composed of one bismuth atom and three phenyl rings. The combination of dc and ac magnetic measurements reveals that one hundred percent of synthesized samples exhibit superconductivity at 3.5 K and/or 7.2 K at ambient pressure. The magnetization hysteresis loops provide a strong piece of evidence of type-II superconductors. It is found that the doped materials crystallize into the triclinic P1 structure, with a mole ratio of 4:1 between potassium and triphenylbismuth. Both the calculated electronic structure and measured Raman spectra indicate that superconductivity is realized by transferring electrons from the K-4s to C-2p orbital. Our study opens an encouraging window for the search of organic superconductors in organometallic molecules.

中文翻译：

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掺钾三苯铋在3.5 K和/或7.2 K下的超导性

我们开发了超声波处理和低温退火两步合成方法，以探索由一个铋原子和三个苯环组成的掺钾三苯基铋的超导性。直流和交流磁测量的组合显示，在环境压力下，100％的合成样品在3.5 K和/或7.2 K时表现出超导性。磁化磁滞回线为II型超导体提供了有力的证据。发现掺杂的材料结晶成三斜晶的P1结构，钾和三苯基铋之间的摩尔比为4：1。计算出的电子结构和测得的拉曼光谱都表明，超导是通过将电子从K-4s转移到C-2p轨道来实现的。