Bustarret E, Kacmarcik J, Marcenat C, Gheeraert E, Cytermann C, Marcus J, Klein T
Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS, B.P.166, 38042 Grenoble Cedex 9, France.
Phys Rev Lett. 2004 Dec 3;93(23):237005. doi: 10.1103/PhysRevLett.93.237005. Epub 2004 Dec 1.
Homoepitaxial diamond layers doped with boron in the 10(20)-10(21) cm(-3) range are shown to be type II superconductors with sharp transitions (approximately 0.2 K) at temperatures increasing from 0 to 2.1 K with boron contents. The critical concentration for the onset of superconductivity in those 001-oriented single-crystalline films is about 5-7 10(20) cm(-3). The H-T phase diagram has been obtained from transport and ac-susceptibility measurements down to 300 mK.
掺杂硼浓度在10(20)-10(21) cm(-3)范围内的同质外延金刚石层被证明是II型超导体，随着硼含量增加，其转变温度从0升高到2.1 K，转变十分尖锐（约0.2 K）。在那些001取向的单晶薄膜中，超导起始的临界浓度约为5-7×10(20) cm(-3)。通过对低至300 mK的输运和交流磁化率测量，获得了H-T相图。
