Enormous Variation in Homogeneity and Other Anomalous Features of Room Temperature Superconductor Samples: A Comment on Nature 615, 244 (2023)
J. E. Hirsch
Abstract
Abstract The resistive transition width of a recently discovered room temperature near-ambient-pressure hydride superconductor [1] changes by more than three orders of magnitude between different samples, with the transition temperature nearly unchanged. For the narrowest transitions, the transition width relative to $$T_c$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>T</mml:mi><mml:mi>c</mml:mi></mml:msub></mml:math> is only $$0.014 \%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.014</mml:mn><mml:mo>%</mml:mo></mml:mrow></mml:math> . The voltage-current characteristics indicate vanishing critical current, and the normal state resistance is unusually small. These anomalous behaviors and other issues indicate that this system is not a superconductor. Implications for other hydrides are discussed.