What is hysteresis?

To clarify what hysteresis is, we must first look at the term itself. The hysteresis comes from the Greek histeros (ὕστερος), which can be translated as "posterior". Hysteresis is translated into German as "aftereffect".

This is exactly what hysteresis is all about. Therefore, a general definition of the term is: "It is the tendency of a material to retain one of its properties, in the absence of the stimulus that has generated it".

Consequently, the principle of hysteresis can be applied to a wide variety of areas, from electronic phenomena to economic phenomena and ferromagnetism.

What is magnetic product hysteresis?

Ferromagnetic materials can be magnetically charged by external magnetic fields. This magnetisation increases much faster than it decreases when the external magnetic field is switched off again.

It is precisely this effect that we owe to hysteresis, which is measured by the hysteresis curve. The magnetic force that remains when the external magnetic field is completely off is what we call remanence.

Let's look at an example of a non-magnetized ferromagnetic material.

For example, through an electric coil, we can magnetize this material. The external magnetic field is denoted (H) and the resulting magnetic field inside is the magnetic flux density (B). Here we are dealing with two variables, the magnetic field strength (H) and the magnetic flux density (B), with hysteresis being the relationship between the two.

If both values were previously at zero, i.e. the coil has not yet been electrified and the material to be magnetized does not yet have its own magnetic energy, a hysteresis curve is formed, which we call the new curve. As the magnetic field strength (H) gradually increases, the magnetic flux density (B) slowly increases at first and eventually reaches a saturation point. Even if (H) increases more, (B) will not increase more.

Consequently, the external magnetic field can be deactivated again and the intensity of the newly created magnetic field will not decrease with the same speed, but only gradually, since we are now talking about the remanence of the material to be magnetized.

Now there are different hysteresis curves: the soft one and the hard one. Soft magnets have narrower curves, smaller remanence and coercive field forces. In contrast, with hard magnets we can observe wider curves, as well as higher remanence values and coercive field forces.

The topic of hysteresis is extensive and can be seen from both the physical and mathematical sides. In this article, however, we initially wanted to clarify the basic principle and general definition of hysteresis. If you have further questions, you can contact us at any time and our experts will be happy to help you.