Group Members: Erick IciarteKelly Mann

Daniel WillisMiguel Lastres

How it works A superconductor is a material that exhibits zero

resistance when exposed to very cold temperatures.

Temperatures required for super conductance range from -234 C or -398 F and beyond.

They will no longer poses their low resistive states when placed in the presence of too large a magnetic field.

…… Super conductance only occurs when the material cools

below it’s critical temperature. Like a critical temperature, there is also a critical magnetic

field. Superconductors will cease to super conduct when an external magnetic field is applied that exceeds the critical magnetic field.

Meissner EffectThe Meissner Effect refers to the complete expulsion of magnetic fields

from the interior of a superconductor. The magnetic field intensity is zero within the superconductor. Electric currents are set up near the surface. Their resulting magnetic

fields cancel the internally applied magnetic field. These current are know as persistent currents.

Persistent currents are the reason there areSuperconductors.

Types of Superconductors There are type 1 and type 2 superconductors. Type 1 superconductors were discovered first and

require the coldest temperatures to exhibit super conductance.

Type 1 superconductors have perfect diamagnetism . Type 1 superconductors only have 1 critical magnetic

field and as a result, are not versatile.

Type 2 Superconductor Main difference is that type 2 superconductors have 2 critical magnetic fields. Used in MRI machines. Below the lower critical field, the material will super conduct. Above the upper critical

field, the material will cease to super conduct. In-between the two levels is a mixed state in which some parts of the metal super conduct as opposed to other parts of the material the conduct electricity normally.

The closer the magnetic field is to the upper critical field, the less superconductive it becomes. As a result, type 2 semiconductors can exhibit their superconductivity in the presence of greater magnetic fields.

Quantum Levitation Done by a quantum effect called quantum locking also

called flux pinning. Only type-II superconductors can be penetrated by

magnetic fields. Flux pinning is closely related to the Meissnet Effect

but with the difference that it allows the magnetic flux to enter in quantized packets which form the flux tubes.

1 µm thick superconducting disk super cooled with liquid nitrogen.

Super cooling provides less energy to knock electrons from there initial path.

Flux Tubes

https://www.youtube.com/watch?v=_F-VVmMD4_k

MagSurf

https://www.youtube.com/watch?v=-QPKq7PHy6c

Hula hoop Ring

SQUIDSQUIDSuperconducting Quantum Interference

Device

What is a SQUID???

A superconducting quantum interference device (SQUID)

Josephson Junction

SQUID Design

SQUID UsesOne of the device's most promising uses is in

magnetoencephalography (MEG).

Physical processes.

DC SQUIDs

Example

Atomic Magnetometer

SQUID Helmet

• Heike Kamerlingh Onnes discovered superconductivity on April 8, 1911

• At 4.2 K the resistance in a solid mercury wire immersed in liquid helium suddenly vanished

• Nobel prize in 1913• Many have continued the research he started

many decades ago

Uses of Superconductors Transport vehicles, such as trains MLX01 test vehicle attained a speed of 361 mph Performs a life-saving function in the medical field

- - more precise than MRI Transmission of commercial power to cities – not

practical over long distances

The Research Continues… UTK is collaborating with ORNL to probe enzyme

function by using a superconducting magnet and supercomputing

Tennessee Tech has been awarded a project by the DOE that features a feasibility study of superconducting cables

China’s Tsinghua University and U.S. DOE’s Berkley Lab are working on high-temperature superconductivity

Last, but not least, we can’t forget our favorite teacher!

Citation http://www.tntech.edu/pressreleases/ttu-energy-experts-working-to-lower-costs-

increase-efficiency-in-electric-power/ http://en.wikipedia.org/wiki/Heike_Kamerlingh_Onnes#Superconductivity http://www.nics.tennessee.edu/superconducting-magnet-and-supercomputing http://superconductors.org/uses.htm http://superconductors.org/history.htm http://www.photo.tntech.edu/Brook_Abegaz_g163.html

http://searchcio-midmarket.techtarget.com/definition/superconducting-quantum-interference-device

http://www.nanogallery.info/nanogallery/?ipg=156 http://medicalphysicsweb.org/cws/article/research/49402 http://en.wikipedia.org/wiki/Flux_pinning