Superconductivity and magnetism and their interplay in quaternary borocarbides RNi₂B₂C

Observation of an anisotropic effect of antiferromagnetic ordering on the superconducting gap in ErNi2B2C

“…As a result, T c of these compounds is appreciably lower in comparison with nonmagnetic borocarbides (R=Y, Lu [1,2,3]). The object of this study, ErNi 2 B 2 C, undergoes a superconducting transition at T c ∼11 K [1,2,3] and two magnetic transitions below T c , which do not destroy superconductivity. The AFM ordering occurs at the Neel temperature T N ∼6 K when the Er ions form a transverse-polarized incommensurate spin-density wave state [1,2,3].…”

“…Quaternary intermetallic nickel borocarbides (hereafter borocarbides) of the RNi 2 B 2 C type (R is a rareearth element) attract special interest (see surveys [1,2,3] and further references) as they include compounds with rather high superconducting transition temperatures (up to T c ≈17 K, R=Lu) and compounds with different types of magnetic ordering that include states with commensurate and incommensurate spin-density waves.…”

“…As a result, T c of these compounds is appreciably lower in comparison with nonmagnetic borocarbides (R=Y, Lu [1,2,3]). The object of this study, ErNi 2 B 2 C, undergoes a superconducting transition at T c ∼11 K [1,2,3] and two magnetic transitions below T c , which do not destroy superconductivity.…”

“…The object of this study, ErNi 2 B 2 C, undergoes a superconducting transition at T c ∼11 K [1,2,3] and two magnetic transitions below T c , which do not destroy superconductivity. The AFM ordering occurs at the Neel temperature T N ∼6 K when the Er ions form a transverse-polarized incommensurate spin-density wave state [1,2,3]. The AFM ordering entails structural distortions and thus reduces the crystal symmetry from tetragonal to orthorhombic [9].…”

Superconductivity in the ternary ZrVGe compound

“…This compound crystallizes in CeScSi or UGeTe prototype structure belonging to the tetragonal I4/mmm space group with lattice parameters a = 3.754 Å and c = 14.488 Å. This prototype structure it is similar to the quaternary LuNi 2 B 2 C which is the prototype structure of many boron-carbide superconducting materials which offer interesting opportunities for the study of multiband behavior and the coexistence between superconductivity and magnetism [8][9][10][11][12][13][14]. Indeed, superconductivity in layer compounds often produces unusual results and at the same time offers a modern view for the occurrence of superconductivity [9][10][11][12][13][14].…”