Superconducting transition table

Figure 8.6 shows the definition of transition temperature Tc and transition width Wc. To remark how the purity of the material and the magnetic field influence the two parameters, we will report hereafter the measurements of the superconducting transition of titanium samples of different purity and in the presence of different magnetic fields. The transitions of four Ti samples, whose characteristics are reported in Table 8.12, are shown in Fig. 8.7 where a change of only 0.2% in purity dramatically moves both the transition... 

Fig. 8.8. Superconductive transitions of die Ti sample D of Table 8.12 in a magnetic Field (0-148G).

The superconducting transition temperatures for selected chemical elements and certain metallic alloys are presented in Table 1. These data and those presented throughout this Chapter have been taken, for the most part, from the excellent compilation by B. W. Roberts (3). 

TABLE 1 Superconducting Transition Temperatures for Selected Elements and Alloys. 

TABLE 9 Reported Superconducting Transition Temperatures in the LiTi204 System. 

Substitution of other transition metal ions for Cu, however, was observed (174) to be highly deleterious to superconducting behavior. Table 14 shows the results of 10% metal-ion substitution in the Cu sites. 

Table 13.1 Superconducting transition temperatures for selected substances... 

Table 2 shows the known RT2B2C compounds (R Sc, Y, La, Th, or 4f or 5f elements T 3d, 4d, or 5d elements). As many as six compounds of this type are known for R = Ce (Mazumdar and Nagarajan, 2005) as well as for La. Table 3 contains the superconducting compounds listed in Table 2 and their superconducting transition temperatures Tc and, if existing, the magnetic ordering tempera-... 

TABLE 3 Borocarbide superconductors with LuNi2B2C-type structure and their superconducting transition temperature Tc and magnetic ordering temperature Tn ... 

Table 1. Superconducting properties of the samples label, nominal composition, lattice constants a and c, onset of superconducting transition as measured by susceptibility (1-3) or deduced from lattice parameters6 (4-5), isotropic shift CT so and fidl width at half maximum A...

Some homoleptic unsymmetrical (dmit/mnt, dmit/tdas) dithiolene nickel complex-based D-A compounds with D = TTF and EDT-TTF also exhibit metal-like conductivity (see Table I) (101). Their molecular structure is shown in Scheme 3. The unsymmetrical tetraalkylammonium salts [MLjLJ- (M = Ni, Pd, Pt) have been prepared by ligand exchange reaction between tetraalkylammonium salts of MLj and ML21 (128, 129) and the D-A compounds have been synthesized by electrooxidation. Among these complexes, only the Ni derivatives exhibit metallic-like properties, namely, TTF[Ni(dmit)(mnt)] (metallic down to --30 K), a-EDT-TTF[Ni(dmit)(mnt)] (metallic down to 30 K), TTF[Ni(dmit)(tdas)] (metallic down to 4.2 K), and EDT-TTF[Ni(dmit)(tdas)] (metallic down to --50 K) (see Table I). The complex ot-EDT-TTF-[Ni(dmit)(mnt)J is isostructural (130) to a-EDT-TTF[Ni(dmit)2)] [ambient pressure superconductor, Section II.B.2 (124)]. Under pressure, conductivity measurements up to 18 kbar show a monotonous decrease of the resistivity but do not reveal any superconducting transition (101). 

Table 1 Superconducting transition temperature records through the years...

Table 1. Superconducting Transition Temperatures (Tc) of Selected Elements...

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