Magnetism
Magnetism
Magnetism is a property of matter that is a result of the orbiting electrons in atoms. The orbiting electrons cause the atoms to have a magnetic moment associated with an intrinsic angular momentum called 'spin'. Magnetic field strengths are measured in units of gauss (G) and Tesla (T). One Tesla is equal to 10,000 gauss. The earth's magnetic field is about 0.5 gauss. The strength of electromagnets used to pick up cars in junk yards is about the field strength of MRI machines (1.5-2.0T). You will run across four terms describing the magnetic properties of materials, such as contrast agents, used in MRI. These terms are ferromagnetism, paramagnetism, superparamagnetism, and diamagnetism