Fri 11 May, 2007 01:28 pm
Hello. Can someone briefly explain how paramagnetism works and what sets it apart from other forms of magnetism (ferromagnetism, electromagnetism, etc.)?
reply to all posters
Do paramagnets only work in the presence of a magnetic field?
How is superparamagnetism different from paramagnetism?
Paramagnetism means that the substance merely has a partially positive magnetic susceptibility and partially aligns its structure wrt an applied magnetic field, but itself has no spontaneous magnetic oer.
We use it in field magnetometry to map deposits of iron containing minerals that will have a partial susceptibility. Superparamag just means that the internal particles (which are ferrimagnetic) will respond and relax according to a hysteresis curve(the mag moments are constantly fluctuating in accordance with the substance). The use of this(in my field at least) is in remnant field paleo- magnetic investigations
Paramegnetic materials are only magnetic in the presence of an external field. They do not retain their magnetism when the external field is removed.