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تسجيل مستخدم جديدLow temperature transition to a superconducting phase in boron-doped silicon films grown on (001)-oriented silicon wafers
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We report on a detailed analysis of the superconducting properties of boron-doped silicon films grown along the 001 direction by Gas Immersion Laser Doping. The doping concentration cB has been varied up to approx. 10 at.% by increasing the number of laser shots to 500. No superconductivity could be observed down to 40mK for doping level below 2.5 at.%. The critical temperature Tc then increased steeply to reach 0.6K for cB = 8 at%. No hysteresis was found for the transitions in magnetic field, which is characteristic of a type II superconductor. The corresponding upper critical field Hc2(0) was on the order of 1000 G, much smaller than the value previously reported by Bustarret et al. in Nature (London) 444, 465 (2006).
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The discoveries of superconductivity in heavily boron-doped diamond (C:B) in 2004 and silicon (Si:B) in 2006 renew the interest in the superconducting state of semiconductors. Charge-carrier doping of wide-gap semiconductors leads to a metallic phase
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The discoveries of superconductivity in the heavily-boron doped semiconductors diamond (C:B) in 2004 and silicon (Si:B) in 2006 have renewed the interest in the physics of the superconducting state of doped semiconductors. Recently, we discovered sup
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In 2004 the discovery of superconductivity in heavily boron-doped diamond (C:B) led to an increasing interest in the superconducting phases of wide-gap semiconductors. Subsequently superconductivity was found in heavily boron-doped cubic silicon (Si:
B) and recently in the stochiometric mixture of heavily boron-doped silicon carbide (SiC:B). The latter system surprisingly exhibits type-I superconductivity in contrast to the type-II superconductors C:B and Si:B. Here we will focus on the specific heat of two different superconducting samples of boron-doped SiC. One of them contains cubic and hexagonal SiC whereas the other consists mainly of hexagonal SiC without any detectable cubic phase fraction. The electronic specific heat in the superconducting state of both samples SiC:B can be described by either assuming a BCS-type exponentional temperature dependence or a power-law behavior.
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