User Tools

Site Tools


Magnetic properties

Stan Zurek, Magnetic properties, Encyclopedia Magnetica,

Magnetic properties - a collective term referring to various magnetic parameters measurable or attributed to various quantities of magnetic materials.

Typical magnetic properties important from a technical and application viewpoint are:

But this list is not exhaustive as different magnetic quantities are required for different applications, and there can be a very strong relationship between magnetic and other parameters such as mechanical strength, eddy current loss, ease of manufacturing, cost, etc.

Overview of magnetic properties of soft magnetic materials: saturation, permeability, frequency range, material cost1)
Overview of magnetic properties of hard magnetic materials: remanence, coercivity, temperature range, material cost2)
→ → →
Helpful page? Support us!
→ → →
← ← ←
Help us with just $0.10 per month? Come on… ;-)
← ← ←

Measurement of magnetic properties

A family of B-H loops (hysteresis loops) at various amplitudes of AC excitation, for grain-oriented electrical steel magnetised at 50 Hz

Magnetic properties are measured by applying suitable electromagnetic, mechanical, thermal, or other excitation and measuring the response of the material under test. A widely applied method is to measure a family of B-H loops (also referred to as hysteresis loops), by applying known magnetic field strength H and measuring the response of the material in the form of magnetic flux density B.

Ferromagnetic and ferrimagnetic materials are of high practical importance for energy conversion. They behave quasi-linearly at low excitation, but always exhibit magnetic saturation at high excitation. This non-linear behaviour can be quantified from the B-H loops, which also allow measuring permeability (slope of the B-H curve), loss (area of the loop), saturation (maximum value of achievable response), coercivity (H at B=0), remanence (B at H=0), etc.

The number of magnetic properties that can be extracted from such measurement depends on the type of employed measurement apparatus, type of excitation, measurement technology, sensitivity of the test equipment, and so on.

Optimum operating point P for a permanent magnet is where the product B and H reaches maximum BHmax, Br=Jr - remanence, JHc - polarisation coercivity, BHc - induction coercivity, Jsat - magnetic saturation3)

For soft magnetic materials the magnetic properties can be measured by devices such as: permeameter, hysteresisgraph, Epstein frame, single-sheet tester, toroidal sample.

Energy of permanent magnets can be tested by measuring magnetic dipole moment by using Helmholtz coil and the magnet withdrawal method. Magnetic moment can be measured also by the vibrating sample magnetometer or vibrating coil magnetometer.4) These devices can be also used for investigation of magnetic properties of non-magnetic materials (those which do not exhibit strong magnetic response, such as diamagnets, paramagnets, antiferromagnets).5)

However, there are many different types of measurement equipment, with hundreds of possible implementations, so it is not possible to list all the devices. For example, measurement of magnetostriction under stress requires a sophisticated apparatus which can simultaneously apply electromagnetic and mechanical excitation, and at the same time measure the resulting strain.6)

See also


This website uses cookies. By using the website, you agree with storing cookies on your computer. Also you acknowledge that you have read and understand our Privacy Policy. If you do not agree leave the website.More information about cookies
magnetic_properties.txt · Last modified: 2023/09/05 14:14 by stan_zurek

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
CC Attribution-Share Alike 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki
Legal disclaimer: Information provided here is only for educational purposes. Accuracy is not guaranteed or implied. In no event the providers can be held liable to any party for direct, indirect, special, incidental, or consequential damages arising out of the use of this data.

For information on the cookies used on this site refer to Privacy policy and Cookies.