Superconductivity

en · official · sha256:36f5cbc310b5077e4ca53b5098c1f091b7cf77c68445fc86cee74a33fa38f2b5EN

<definition id="fs-id1172099501303"> <term>Cooper pair</term> <meaning id="fs-id1172099501309">coupled electron pair in a superconductor</meaning> </definition>

en · official · sha256:b5ce7c496f6bd44ff9ec346e909ef30e7403162455a30b04f37c63875d72f6d4EN

<definition id="fs-id1172102108624"> <term>critical magnetic field</term> <meaning id="fs-id1172102108629">maximum field required to produce superconductivity</meaning> </definition>

Ссылаются нормы: critical_field_at_absolute_zero

en · official · sha256:986c9d303f48ae33f31d2c81dbb67b845ea023baf4a571c2cfda97231bce6251EN

<para id="fs-id1172102131914">where <m:math><m:mrow><m:msub><m:mi>B</m:mi><m:mtext>c</m:mtext></m:msub><m:mo stretchy="false">(</m:mo><m:mn>0</m:mn><m:mo stretchy="false">)</m:mo></m:mrow></m:math> is the critical field at absolute zero temperature. <link target-id="fs-id1172101922736"/> lists the critical temperatures and fields for two classes of superconductors: <term id="term-00003">type I superconductor</term> and <term id="term-00004">type II superconductor</term>. In general, type I superconductors are elements, such as aluminum and mercury. They are perfectly diamagnetic below a critical field <emphasis effect="italics">B_C</emphasis>(<emphasis effect="italics">T</emphasis>), and enter the normal non-superconducting state once that field is exceeded. The critical fields of type I superconductors are generally quite low (well below one tesla). For this reason, they cannot be used in applications requiring the production of high magnetic fields, which would destroy their superconducting state.</para>

Ссылаются нормы: CriticalFieldFallsAsTemperatureSquared

en · official · sha256:bc439e67571361467442d7ce9653a80bf452156130ee4972c4f2c2a49669f202EN

<definition id="fs-id1172099545829"> <term>critical temperature</term> <meaning id="fs-id1172099545834">maximum temperature to produce superconductivity</meaning> </definition>

Ссылаются нормы: AtOrAboveCriticalTemperatureItDoesNot, BelowCriticalTemperatureItSuperconducts, critical_temperature, temperature_of

en · official · sha256:91f91fba016de9d5e51f7d9293166eb186eb6f95f3574520b53570657accaf79EN

<para id="fs-id1172101758770">In addition to zero electrical resistance, superconductors also have perfect diamagnetism. In other words, in the presence of an applied magnetic field, the net magnetic field within a superconductor is always zero (<link target-id="CNX_UPhysics_42_08_Meissner"/>). Therefore, any magnetic field lines that pass through a superconducting sample when it is in its normal state are expelled once the sample becomes superconducting. These are manifestations of the Meissner effect, which you learned about in the chapter on current and resistance.</para>

Ссылаются нормы: SuperconductorExpelsTheField