Temperature, critical, magnetic

Symbols in tables T Critical temperature Critical magnetic field in the T = 0 limit 6 Debye temperature and y Electronic specific heat. 

Three important characteristics of the superconducting state are the critical temperature, the critical magnetic field, and the critical current. These parameters can be varied by using different materials or giving them special metallurgical treatments. 

Superconductivity exists within the boundaries of three limiting parameters which must not be exceeded the critical temperature (T ), the critical magnetic field (H ) and the critical current demsity (J ). 

For conventional Ising-spin systems, Pising(o ) takes on the expected simple forms namely, either Puingiq) = < (0) in the (high-temperature, zero magnetization) paramagnetic phase or the double-peaked Pising(o ) = 5(q + M ) + 6 q — M ) for temperatures below the Curie critical temperature, T < Tc. 

Transition temperature in Kelvin, critical magnetic field in gauss (1CT4T). 

In Table 3, some data for a family of the most promising A-15 type materials are presented with their critical magnetic fields, and the derivative of critical field with respect to transition temperature (all about 2.5 in value). These data were reported by Hulm and... 

Figure 12a Critical current of a Y-Ba-Cu-O film measured using 10 /xV criterion as a function of temperature in magnetic fields of (from the right) 0.1, 5, 10, and 14 Tesla. The normal state region (I), fully superconducting state (III) and low resistance ohmic state (II) are indicated. The inset shows I-V characteristics of these three regions (III) region has been expanded by a factor 2000. Ref. 37.

Figure 6.10 Temperature dependence of critical magnetic field for a superconductor. Reprinted, by permission, from L. Solymar and D. Walsh, Lectures on the Electrical Properties of Materials, 5th ed., p. 429. Copyright 1993 by Oxford University Press.

Table 6.1 Critical Temperature and Critical Magnetic Field of a Number of Superconducting Elements...

Fig. 44. Temperature dependence of the critical field Her (see Kawano-Funikawa 2001) in dependence on the magnetic prehistory of an ErNi2B2C single crystal. ( ) Virgin curve, ( ) H (perpendicular to c) decreasing, (o) H increasing Tc — critical temperature, Tn — magnetic ordering temperature, Twfm — onset temperature...

Figure 13.17 (a) Typical graph of critical magnetic field 3Cc as a function of temperature for a type I superconductor. Magnetic fields greater than 3tc suppress the superconducting transition, (b) Critical magnetic fields for several type I superconductors. 

Three important characteristics of the superconducting state are the critical temperature, the critical magnetic... 

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