8B - 7_Mag fld_11.ppt

8B - 7_Mag fld_11.ppt - Permanent Magnetic Materials...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Permanent Magnetic Materials Permanent magnetism is found in a few materials, notably iron. The class of permanent magnets is called “ferromagnets”. Note that not all magnets are metals and not all metals are magnets. Electrical conduction and permanent magnetism are unrelated. Ferromagnetism exists below T curie . (Like freezing) Material T curie (K) Fe 1043 Co 1388 Ni 627 Gd 293 Dy 85 CrBr 337 Au 2 MnAl 200 EuO 77 EuS 16.5 MnAs 318 MnBi 670 GdCl 32.2 Fe 2 B 1015 MnB 578
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Some permanent magnets Permanent magnets (compasses) align along the N-S axis. The Earth is a magnet! (W. Gilbert)
Background image of page 2
Permanent or Ferro - Magnets Magnets always have a “north” and a “south” pole. The magnetic lines are the directions of the force on a N pole. (Can imagine a long rod in which the N and S poles are far apart.) Like poles repel, and unlike poles attract. Lines emerge from N pole and enter S pole.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Breaking a magnet does not isolate a N or a S pole. A magnetic
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/02/2011 for the course PHYS 8B taught by Professor Catherinebordel during the Spring '10 term at Berkeley.

Page1 / 17

8B - 7_Mag fld_11.ppt - Permanent Magnetic Materials...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online