Home > Science, Word of the Day
Word of the Day: Diamagnetism (Metals)
Tuesday, November 17th, 2009 | Science, Word of the Day |
Via Wikipedia.

Levitating pyrolytic carbon
Diamagnetism is the property of an object which causes it to create a magnetic field in opposition of an externally applied magnetic field, thus causing a repulsive effect. Specifically, an external magnetic field alters the orbital velocity of electrons around their nuclei, thus changing the magnetic dipole moment in the direction opposing the external field. Diamagnets are materials with a magnetic permeability less than μ0 (a relative permeability less than 1).
Consequently, diamagnetism is a form of magnetism that is only exhibited by a substance in the presence of an externally applied magnetic field. It is generally quite a weak effect in most materials, although superconductors exhibit a strong effect.
Diamagnetic materials cause lines of magnetic flux to curve away from the material, and superconductors can exclude them completely (except for a very thin layer at the surface).
In 1778 S. J. Bergman was the first individual to observe that bismuth and antimony were repelled by magnetic fields. However, the term “diamagnetism” was coined by Michael Faraday in September 1845, when he realized that all materials in nature possessed some form of diamagnetic response to an applied magnetic field.
A thin slice of pyrolytic graphite, which is an unusually strong diamagnetic material, can be stably floated in a magnetic field, such as that from rare earth permanent magnets. This can be done with all components at room temperature, making a visually effective demonstration of diamagnetism.
The Radboud University Nijmegen, the Netherlands, has conducted experiments where water and other substances were successfully levitated. Most spectacularly, a live frog (see figure) was levitated.[3]
See also ferromagnetism and paramagnetism.
Previous WOTD - Veblen Goods and Giffen Goods (Economics)
No comments yet.
Leave a comment
Search
A Word from Our Sponsors
Latest Comments
- OK, but who hasn’t wanted to break Jim Treacher’s knees? (1 comments)
- Infrared Photography Links (4 comments)
- I saw the “G.I. Joe” movie (3 comments)
- Eric Janszen gives the economic gloom and doom, take it or leave it (1 comments)
- George Dickel Cascade Hollow is good stuff (7 comments)
- Hiking Boots, Pajamas, DC Power and Propane (1 comments)
- Range Report: Two .40 calibers - SIG P229 and Glock 23 (107 comments)
Subscribe
Archives by Date
Archives by Category
- A&E
- Best Of
- Blogging
- Comic Books
- Dancing Baloney
- Dear Lazyweb
- E-commerce
- East Tennessee
- Economics
- Environment
- European Union
- Family Tree - Jones Side
- Family Tree - Moore Side
- Food & Drink
- Funny Ha-Ha
- Guns
- Health Care
- Holidays
- Home Life
- Johnia Berry
- Macular Degeneration
- Media Behaving Badly
- Middle East
- Misc
- Municipal Wi-Fi
- News
- Nifty
- Photos
- Political Survival Kit
- Politics
- Polls
- Population
- PSAs
- Quotes
- Rocky Top Brigade
- Science
- Social Security
- Star Wars
- Tech
- The Usual Suspects
- Travel
- True Crime
- Word of the Day





