Asymmetries and shifts of the hysteresis loop give information about material properties which need to be discussed in context of structure, anisotropies,... system set-up and experiment.

The area enclosed in a hysteresis cycle (plotted in proper units) represents the irreversible work required to go through the cycle. Often enough, a single hysteresis cycle cannot reveal much physics beyond such qualitative quantities including squareness etc., which you mention. However, in many cases this is exactly the practically relevant information and thus may prove sufficient.

If you can come up with a specific model of magnetization reversal in your specimen or system then you may be able to check the compatibility of the experimental dataset with your model and determine the parameters of that particular model from the shape of the hysteresis curve. Very different physical mechanisms of magnetization reversal may produce very similar shaped M(H) loops, though.

In case you can produce a dataset that not only includes a so-called "major loop" but also "minor loops", then there exist intelligent recipes to conduct such experiments in a way as to reveal quite a bit about the nature of magnetization reversal in a specimen.

Since finite hysteresis is a sign of non equilibrium, chosing (if available) to perform hysteresis cycles with an appropriate set of field sweep rates may reveal some information about the dynamics in your system.

Furtheron you may look for temperature dependencies, directional anisotropies etc., all of which do relate to specific properties which may be of interest.

Also, you can obtain cualitative information about magnetic exchange interactions between the nanoparticles in the sample. It is very useful to study spring magnets.

I totally agree with all comments given above. In addition, I would remark that is very important to know the nature of your material (If it is a polycristal, is a set of nanoparticles, is anysotropic... ) to interpret the M(H) loops observed.

Additional M-T measurements as ZFC-FC curves and M(H) curves at different temperatures and/or magnetic relaxation measurements would be of special interest to model, test and properly interpret the magnetic properties of your material.

I also agree with all comments. Furthermore, it is important that to know your materials type I mean is it paramagnetic, ferromagnetic or ferrimagnetic..etc. Each type has own features when you want to study the hysteresis loop (shape of the loop). Also, it is interesting to study the magnetization with the change the direction of magnetic field (in-plane or out of plane). Also, measuring the initial magnetization is also interesting.

From the M-H hysteresis curve, we can confirm the type of the materials, ferromagnetic or anti-ferromagnetic, or parametric. In addition is this is soft ferromagnetic or hard ferromagnetic???. Moreover, We can experimentally detect the spin state of the sample, LS, IS, and/or HS states in a simple way. If we study M-H with changing temperature we can also detect the transition temperature (TC) and the phase separation and phase boundary too. Moreover, we can detect the swishing shape of the curves.

Considering the Temperature evolution of the M(H) curves and in particular of the coercive field, it is also possible to distinguish between the pinning mechanisms (weak or strong) that occur in your systems. This study is very useful not only for bulk samples but also for thin films with hard magnetic character, for example, or also in exchange spring films (i. E. hard -soft coupled bilayers)

One can also try approach-to-saturation law on virgin curve at high fields to get some insights into the nature of magnetic anisotropy, high field susceptibility, etc.,. The information about this can be found in any basic magnetism book.

I also agree with all given comments.

Just add a pieces, first of all: what kind of specimen u have, how u treat it, what is the instrument (capability), how u prepare the sample for analysis etc.

Example: u can plot a minor loop (isothermal magnetization-demagnetization) to know how the exchange interaction work in your specimen.

M-H curve is sensitive with the external filed direction relative to the sample anisotropy (crystal and or shape). U can get a lot more info, even u can tailoring ur specimen by understand this curve only.

There a few model to fit the curve that u can use to extract some more information such as Energetic model, Hodgdon, Langevin, Jiles-Atherton, Preisach etc.

Hope it help.

By differentiating lower branch of the hysteresis curve you obtain the so called switching field distribution.

From an application point of view the (major) hysteresis loop of soft magnetic materials contains a wealth of information about the power loss and dc-bias behaviour of an inductive component for both simulation and design purposes.

@Marek, but in order to obtain it, you need a model for the hysteresis, I would say. We must discriminate between magnetization reduction by rotation (reversible) and by switching (irreversible). In general, this distinction cannot be made from experiment alone with a single (major) M(H) loop.

Kai, you're right, of course. That's why I was always amazed to see switching field distribution defined this way in manuals coming with VSM instruments. Maybe, this very rough estimate is sufficient for engineers working with applications of magnetic materials (permanent magnets, magnetic recording, etc.). Surely, Preisach map is much better approximation.

@Kai Fauth: As in your first reply you have mentioned "The area enclosed in a hysteresis cycle (plotted in proper units) represents the irreversible work required to go through the cycle". May you please mention what should be the proper units? Is it to calculate hysteresis loss and/or gain?

Some researchers are able (at least they say so) to extract (uniaxial?) anisotropy constant from major hysteresis loop. For this purpose an upper branch between zero and saturation field is used. Loosely speaking, the distance between this branch and M-axis plays a role. More precisely, an area between horizontal line at saturation and upper branch of hysteresis curve, for positive exciting fields (a curvilinear triangle), is the object of investigations.

There is also some literature investigating the so called "approach to saturation". The technical parameter, called "magnetic hardness", derived from such measurements, is again related to magnetic anisotropy. Here the lower branch is used, at high positive exciting field.

Loop area is equal the work of the magnetization reversal

Area enclosed by the loop is a measure of loss,

Type of magnetic material can be classified by studying M-H loop.

besides all, magnetization reversal mechanism could be understood by M-H. Sharp coercive shift tells us that the material has good switching characteristic ideal for devices that run on spin

S.N. Piramanayagam makes an important point: in general, a single M(H) loop is not very informative concerning the mechanism of magnetization reversal. The difficulty lies in telling apart reversible rotation and rotation that involves switching, let alone reversal by moving domain walls etc.

If deeper insight is to be obtained, there exists a number of intelligent protocols of doing multiple, partial M(H) loops which allow checking for, e.g. the amount of irreversible switching in a portion of an M(H) loop.

This link may give some more information regarding M~ H curve http://magician.ucsd.edu/essentials/WebBookse28.html

We can also get permeability as well as reluctance from M-H curve...as..... permeability = B/H........Good Luck...........

@ Ashish pls what is conventional EB phenomenon.

Oseoghaghare, "EB" most probably is meant to be "exchange bias".

What are the experimental steps required to ensure whether the studied system exhibit Exchange Bias phenomenon?

It depends on the character of your exchange bias system, the instrumental possibilities and the kind of (essentially thermal) treatment you can apply to your specimens.

Maybe the simplest test, when you observe a shifted hysteresis loop, is to systematically vary the specimen orientation. When your sample is rotated by 180 degrees about an axis perpendicular to the magnetic field, then the shift of the magnetization loop should occur in the opposite direction.

One possible difficulty is the so-called training effect: not few EB systems show a variation of the magnitude (progressive reduction) of the EB shift as a function of the number of magnetic field cycles they have been exposed to. This is connected with the microscopic magnetic configuration of the interface between the layers causing the EB effect.

The "classical" EB effect occures at the interface between a ferromagnet and an antiferromagnet chosen such that the Neel temperature (TN) of the AFM is well below the Curie temperature (TC) of the FM.

Heat the specimen above TN (if you can, measure M(H) at this temperature). There will be no shift. Cool the specimen through TN with the magnetic field saturating the ferromagnet. the next M(H) cycle shall display a displacement towards the opposed field direction.

Do all of the above again, but with the opposite orientation of the field during cooldown. Then also the EB shift will have changed sign.

Thanks

Thanks