Quaternary borocarbide superconductor

Soon after the discovery of the quaternary borocarbide superconductors in 1994 a remarkable progress in the investigation of their physical properties could be asserted (Muller and Narozhnyi, 2001b). One reason for this rapid progress is the favorable synthesis properties of this class of materials, which resulted in high-quality polycrystalline samples over a wide range of compositions, as well as thin... 

After a short report on the discovery of the quaternary borocarbide superconductors in Section 1.1, for comparison a limited survey of other superconductors based on boron and/or carbon will be presented in Section 1.2 whereas the interplay of superconductivity and magnetism in other materials is discussed in Section 1.3. At the end of this section some special features of the RNi2B2C compounds and review articles in this field can be found in Section 1.4 as well as the further outline of this chapter. 

With the discovery of superconductivity (Tc = 15.5 K) in the Y-Ni-B-C system [6, 80], a new class of quaternary borocarbide superconductors has emerged. Superconductivity has been observed in several rare earth (Lu, Tm, Er and Ho) nickel borocarbides[80], and with transition metals such as Pd and Pt. The superconducting phase having the composition of YNi2B2C, crystallizes [81] in a tetragonal structure with alternating Y-C and Ni2B2 layers. Band structure calculations [82] indicate that these materials, unlike cuprate superconductors, are three-dimensional metals. 

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