2008/03/07 by M. Kriener, Y. Maeno, T. Oguchi +9
Engineering · Materials Science · Physics and Astronomy · #Boron and Carbon Nanomaterials Research #Diamond and Carbon-based Materials Research #Silicon Carbide Semiconductor Technologies #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.78.024517
published as Phys. Rev. B 78, 024517 (2008) · 9 pages, 7 figures, 2 tables, submitted to Phys. Rev. B
arxiv created 2008/03/07 · openalex publication_date 2008/07/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The discoveries of superconductivity in the heavily-boron doped semiconductors diamond (C:B) in 2004 [Ekimov et al., Nature (London) 428, 542 (2004)] and silicon (Si:B) in 2006 [Bustarret et al., Nature (London) 444, 465 (2006)] have renewed the interest in the physics of the superconducting state of doped semiconductors. Recently, we discovered superconductivity in the closely related ``mixed'' system heavily boron-doped silcon carbide (SiC:B) [Ren et al., J. Phys. Soc. Jpn. 76, 103710 (2007)]. Interestingly, the latter compound is a type-I superconductor whereas the two aforementioned materials are type II. In this paper, we present an extensive analysis of our recent specific-heat study, as well as the band structure and expected Fermi surfaces. We observe an apparent quadratic temperature dependence of the electronic specific heat in the superconducting state. Possible reasons are a nodal gap structure or a residual density of states due to nonsuperconducting parts of the sample. The basic superconducting parameters are estimated in a Ginzburg-Landau framework. We compare and discuss our results with those reported for C:B and Si:B. Finally, we comment on possible origins of the difference in the superconductivity of SiC:B compared to the two ``parent'' materials C:B and Si:B.