Department of Physics , National Dong Hwa University , Hualien 97401 , Taiwan.
Inorg Chem. 2018 Aug 6;57(15):9306-9315. doi: 10.1021/acs.inorgchem.8b01303. Epub 2018 Jul 11.
Electron-phonon coupling is a fundamental inelastic interaction in solid-state physics and superconductors. Here we probe electron-phonon and superconducting coupling strength by tuning the indium composition in In Pb superconducting bimetallic alloys. A crossover from weak to strong coupling strength was observed through the analysis of crystal structure and superconducting phase diagrams. The hole-doped Pb solid solution showed suppressed T and subverted coupling strength due to decreased density of state N(0) and hardened phonons, while the electron-doped In solid solution revealed enhanced T and stronger coupling strength because of increased N(0) and softened phonons. Our results are in agreement with the Ginzburg-Landau theory calculations regarding the dirty limits and are well described by the Allen and Dynes formula within the framework of the McMillan formalism.
电子-声子耦合是固态物理和超导体中的一种基本非弹性相互作用。在这里，我们通过调节 In-Pb 超导双金属合金中的铟成分来探测电子-声子和超导耦合强度。通过分析晶体结构和超导相图，观察到从弱耦合强度到强耦合强度的转变。由于态密度 N(0)减少和声子变硬，掺杂空穴的 Pb 固溶体显示出 T 的抑制和耦合强度的反转，而掺杂电子的 In 固溶体则显示出 T 的增强和耦合强度的增强，这是由于 N(0)增加和声子软化所致。我们的结果与关于脏极限的吉布斯-朗道理论计算一致，并在麦克米兰形式主义框架内的艾伦和戴恩斯公式的范围内得到很好的描述。
