Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
high-Tc superconductor
Directory
References
Discover
Ahura Mazda - relief of the Zoroastrian god Ahura Mazda at the ancient ruins of Persepolis in Iran. Also known as Ormazd Zoroastrianism,
Which Religion Is the Oldest?
Fish. Lionfish. Lion-fish. Turkey fish. Fire-fish. Red lionfish. Pterois volitans. Venomous fin spines. Coral reefs. Underwater. Ocean. Red lionfish swims by seaweed.
10 of the World’s Most Dangerous Fish
Easter Procession of Maria Santisima del Sacromonte in Granada, Spain. This statue is known as Virgen de los Gitanos or The Virgin of the Gypsies.
What is Holy Week?
Illustration for Demystified "How Dangerous is Quicksand"
How Deadly Is Quicksand?
African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.
Timeline of the American Civil Rights Movement
Entrants falling and tumbling over while chasing the cheese at the 2016 'Cheese Rolling' held at Cooper's Hill, in the Cotswolds, Brockworth England
7 of the World’s Most Dangerous Festivals
New Zealand. Political/Physical map. Includes locator.
Where Is “Old Zealand”?

high-Tc superconductor

physics
Also known as: high-transitional temperature superconductor, higher-temperature superconductor

Learn about this topic in these articles:

ceramics

  • Figure 1: Schematic diagram of a zirconia oxygen sensor used to monitor automobile exhaust gases. The sensor, approximately the size of a spark plug, is fitted into the exhaust manifold of an automobile engine. The thimble-shaped zirconia sensor, sandwiched between thin layers of porous platinum, is exposed on its interior to outside air and on its exterior to exhaust gas passing through slits in the sensor shield. The two platinum surfaces serve as electrodes, conducting a voltage across the zirconia that varies according to the difference in oxygen content between the exhaust gas and the outside air.
    In conductive ceramics: Superconductors

    …ceramic conductors are the so-called high Tc superconductors, materials that lose their resistance at much higher critical temperatures than their metal alloy counterparts. Most high Tc ceramics are layered structures, with two-dimensional copper-oxygen sheets along which superconduction takes place. The first of these was discovered in 1986 by the Swiss…

    Read More
  • In electroceramics

    …are referred to as high-Tc superconductors.

    Read More

superconductivity

  • Figure 1: Specific heat in the normal (Cen) and superconducting (Ces) states of a classic superconductor as a function of absolute temperature. The two functions are identical at the transition temperature (Tc) and above Tc.
    In superconductivity: Thermal properties of superconductors

    …been found to have extraordinarily high transition temperatures, denoted Tc. This is the temperature below which a substance is superconducting. The properties of these high-Tc compounds are different in some respects from those of the types of superconductors known prior to 1986, which will be referred to as classic superconductors…

    Read More
  • Figure 1: Specific heat in the normal (Cen) and superconducting (Ces) states of a classic superconductor as a function of absolute temperature. The two functions are identical at the transition temperature (Tc) and above Tc.
    In superconductivity: Higher-temperature superconductivity

    Ever since Kamerlingh Onnes discovered that mercury becomes superconducting at temperatures less than 4 K, scientists have been searching for superconducting materials with higher transition temperatures. Until 1986 a compound of niobium and germanium (Nb3Ge) had

    Read More
Britannica Chatbot logo

Britannica Chatbot

Chatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.
Josephson effect
Table of Contents
Introduction References & Edit History Related Topics
Images
Figure 3: Maximum zero-voltage (Josephson) current passing through a junction by Cooper-pair tunneling as a function of magnetic field.
Related Questions
Read Next
Products from aluminum, copper, bronze, and brass on a white background. (metals)
Why Are Some Metals More Conductive than Others?
Discover
Marriage. A couple getting married during a church wedding ceremony. (religion, ceremony, bride, groom)
The Seven Sacraments of the Roman Catholic church
Statue of Nostradamus
Nostradamus and His Prophecies
New Zealand. Political/Physical map. Includes locator.
Where Is “Old Zealand”?
Ahura Mazda - relief of the Zoroastrian god Ahura Mazda at the ancient ruins of Persepolis in Iran. Also known as Ormazd Zoroastrianism,
Which Religion Is the Oldest?
Battle of the Alamo from "Texas: An Epitome of Texas History from the Filibustering and Revolutionary Eras to the Independence of the Republic, 1897. Texas Revolution, Texas revolt, Texas independence, Texas history.
6 Wars of Independence
July, 2006, Launch of Space Shuttle Discovery STS-121. See attached for full caption information.
Will Light-Speed Space Travel Ever Be Possible?
Two chicks near an egg with a white background (poultry, chick, chickens, birds).
What Do Eggs Have to Do with Easter?

Josephson effect

electronics
External Websites
Written and fact-checked by
The Editors of Encyclopaedia Britannica
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.
The Editors of Encyclopaedia Britannica
Article History
Key People:
Brian D. Josephson

Josephson effect, flow of electric current between two pieces of superconducting material separated by a thin layer of insulating material. Superconductors are materials that lose all electrical resistance when cooled below a certain temperature near absolute zero. The English physicist Brian D. Josephson predicted the flow of current in 1962 on the basis of the BCS theory (q.v.) of superconductivity. The subsequent experimental verification of the Josephson effect lent support to the BCS theory.

The Josephson current flows only if no battery is connected across the two superconductors. If a battery is inserted, the current oscillates very rapidly so that no net current flows. The presence of magnetic fields near the superconductors influences the Josephson effect, allowing it to be used to measure very weak magnetic fields.

According to the BCS theory, superconductivity is a result of the correlated motion of electrons in the superconducting solid. Part of this correlation is the formation of pairs of electrons called Cooper pairs. According to Josephson, under certain circumstances these Cooper pairs move from one superconductor to the other across the thin insulating layer. Such motion of pairs of electrons constitutes the Josephson current, and the process by which the pairs cross the insulating layer is called Josephson tunneling.

The Josephson effect is central to the operation of the superconducting quantum interference device (SQUID), which is a very sensitive detector of magnetic fields. It is used to measure tiny variations in the magnetic field of the Earth and also of the human body.

This article was most recently revised and updated by William L. Hosch.
Britannica Chatbot logo

Britannica Chatbot

Chatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.