Abstract
Type-I superconductivity was recently reported for the Dirac semimetal ( K) with, remarkably, multiple critical fields and a complex phase diagram. Here, measurements of the specific heat utilizing a thermal relaxation technique are presented. Conventional weak-coupling BCS superconductivity is confirmed by examining the temperature dependence of the specific heat in zero field. By probing the latent heat accompanying the superconducting transition, thermodynamic evidence for type-I superconductivity is attained. The presence of the intermediate state is observed as a significant broadening of the superconducting transition onto lower temperatures at high fields as well as irreversibility in the specific heat in zero-field-cooled data at 8.5 mT.
- Received 12 September 2020
- Revised 8 February 2021
- Accepted 9 February 2021
DOI:https://doi.org/10.1103/PhysRevB.103.104502
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