Nearly twofold overestimation of the superconducting volume fraction in pressurized Ruddlesden-Popper nickelates

摘要

本研究指出，Zhu等人在测量加压Ruddlesden-Popper镍酸盐La₄Ni₃O₁₀的超导体积分数时，采用了此前未见报道的计算方程，导致结果被显著高估。作者基于Zhu等人公布的原始数据，使用标准超导磁矩计算方法重新分析，发现超导体积分数仅为51%至59%，而非Zhu等人报告的81%至86%。通过检查Zhu等人提供的方程及其推导，作者发现该方程在计算中错误地使用了样品几何参数，导致对超导相所占体积比例的计算出现约两倍的高估。作者以假想样品为例，说明即使超导相实际只占50%，该方程仍会得出接近100%的结果。因此，该错误影响了迄今所有已报道的Ruddlesden-Popper镍酸盐超导体积分数数据，需要重新审视这些结论。

材料

• La₄Ni₃O₁₀

方法

• demagnetization factor calculation
• magnetic moment analysis

关键词

• superconducting volume fraction
• demagnetization factor
• meissner effect

亮点

• Identifies a systematic error in the calculation of superconducting volume fraction in pressurized nickelates.
• Demonstrates with a hypothetical example that even a 50% superconducting fraction would yield near 100% using the incorrect equation.

结论

• The equation used by Zhu et al. to calculate superconducting volume fraction in La₄Ni₃O₁₀ is incorrect.
• The correct calculation yields a superconducting volume fraction of 51-59%, not 81-86% as reported.
• The error arises from using an incorrect formula that effectively doubles the volume fraction.
• This error affects all previously reported superconducting volume fractions in Ruddlesden-Popper nickelates.

主要论断

• The equation used by Zhu et al. overestimates the superconducting volume fraction in La₄Ni₃O₁₀ by nearly twofold
  • 证据: From abstract: 'the proposed equation and procedure are incorrect, and that this equation results in multiple overestimations of the superconducting volume fraction in the sample',Calculations show ZFC ratio 51-59% vs reported 81-86%

研究流程

本批次暂无数据。