Critical Field
The upper critical field (UCF) is the magnetic field (usually expressed in teslas (T)) which completely suppresses superconductivity in a Type II superconductor at 0K (absolute zero).
More properly, the UCF is a function of temperature (and pressure) and if these are not specified absolute zero and standard pressure are implied.
Werthamer–Helfand–Hohenberg theory predicts the upper critical field (Hc2) at 0 K from Tc and the slope of Hc2 at Tc.
The UCF (at 0 K) can also be estimated from the coherence length(ξ) using the Ginzburg-Landau expression : Hc2 = 2.07 x 10-15 Tm2/(2 Pi ξ2)
Articles on superconductivity use Hc2 or Bc2 interchangeably since the materials are rarely magnetic.
Read more about Critical Field: Lower Critical Field
Famous quotes containing the words critical and/or field:
“The critical method which denies literary modernity would appear—and even, in certain respects, would be—the most modern of critical movements.”
—Paul Deman (1919–1983)
“In the field of world policy I would dedicate this Nation to the policy of the Good Neighbor—the neighbor who resolutely respects himself and, because he does, respects the rights of others—the neighbor who respects his obligations and respects the sanctity of his agreements in and with a world of neighbors.”
—Franklin D. Roosevelt (1882–1945)