A better explanation can be given if the details are known.

1. What is the magnetic nature of the sample ? Ferro/Ferri/Antiferro etc.

2. At what value of H, MT recorded?

3. Whether it is Zero Field Cooled or Field Cooled Measurement.

4. In MH variation what situation was, that value obtained? During the first rising of the field or second or, during decreasing of field value from the maximum. It will be best if those variations can be seen.

Actually, the reason behind asking this question is, magnetization value is not only an instantaneous value of a particular situation but rather depends on its previous situations. As the value 31 emu/cc is relatively high, I can guess the sample is ordered magnetic (Ferro/Ferri/Antiferro).

For an ordered magnetic system, all the moments don't behave the same at a fixed temperature and field.

Now for that MT curve measured during the rising of temperature, after cooling the sample to 50 K from 400 K in absence of field (Considering ZFC), some moments will get blocked and couldn't take part in external measurements (Considering nanoparticle). So the moment value obtained here will be less than the maximum value that can be obtained there.

Similarly for the MH loop, due to the presence of hysteresis, the value of magnetization would be less during the first rising (virgin curve) than that during decreasing of the field, though the field is same in both cases.

Dear Sudhanshu Dwivedi,

you have provided insufficient information for a correct judgment.

At the same time, Sukhendu Sadhukhan has given you a very competent answer.

In addition, there are also such questions. Were the measurements carried out on the same equipment and by the same method? Have you used the VSM method? In which field was the curve M(T) recorded? Was the orientation of the film relative to the field the same in both cases?

Sukhendu Sadhukhan Please find attached both the images in my edited question. My question is that the typical value of M occurring at 300 K (of 31.5 emu/cc) from the MT curve happens to occur at around 400 Oe of the applied field at room temperature in MH curve. What is the reason ? How can we compare the values of M from M vs. T and MH curves as both values are differing ?

Sudhanshu Dwivedi, mentioned value of 400 Oe is in the MH loop, right?

What field was applied in MT measurement?

Is it zero field cooled measurement?

Sukhendu Sadhukhan

1. MH loop

2. Zero field cooled

3. Can you tell me fitting procedures for MT & MH curves ?

Yes, but,

What is the value of the field (in Oe) used in MT measurement?

Sukhendu Sadhukhan

ZFC, zero field in MT

I think a misunderstanding occurred.

In your question, you asked,

"How can we compare the values of M from M vs. T and MH curves as both values are differing."

Both values are differing, what are both values? What is their value?

My question is that the typical value of M (of 31.5 emu/cc) occurrs at 300 K from the MT curve.

This value if we see from MH curve happens to occur at around 400 Oe of the applied field at room temperature in MH curve. What is the reason ?

You provided three values

1. Magnetization M = 31.5 emu/cc

2. Temperature T = 300 K.

3. Magnetic Field H = 400 Oe.

How to compare three different quantities?

Like as you said the value of H is 400 Oe in the second case, then what was its value in the first case?

1. Magnetization M = 31.5 emu/cc at 300 K taken from MT curve

2. This same value of M (31.5 emu/cc) occurs at about 400 Oe of field in the MH curve. How it can be accounted for 31.5 emu/cc obtained from the MT curve at 300 K ?

Temperature and Magnetic field are two different independent parameters having no correlation between them. The same value of magnetization (31.5 emu/cc) at 400 Oe in the MH curve and at 300 K in the MT curve is just only a random value. And trying to correlate them doesn't make sense. It doesn't draw any scientific conclusion.

Thank You. Can you suggest me methods, videos or papers to fit MT and MH values ?

You are most welcome. There are lots of different equations/fittings depending on the scenarios/ magnetic nature of the sample. Before that, it is needed to understand the magnetic nature of the sample very well. Search papers for magnetic discussion of your sample. Without knowing your sample nothing can be done.

My sample is half-metallic ferromagnetic. I want to derive as much parameters as I can.

You can check this,

Article Pulsed Laser Deposited Ferromagnetic Chromium Dioxide thin F...

This is my own paper. Plz tell me any papers for fitting of MT and MH curves.

That's a hilarious coincidence.

And also a great thing that it appears at the top of the search result. Congratulation.

However, MT data isn't sufficient for fitting. You can collect data at higher temperatures and FC ZFC measurement if possible. Then a better analysis can be made.

And for MH data try to collect at some different constant temperatures.

Till then I will find some possible analyses for that MH loop and will inform you here.

Though not related to this sample directly, but you can see the magnetic analysis of these two papers of mine.

1. Article Magnetoelectric multiferroicity in a newly derived nanocompo...

2. Article Multiferroic properties and magnetoelectric coupling observe...

Sudhanshu Dwivedi, when it comes to ferro- or ferri- magnetic magnetization you have to heavily consider the history of externally applied magnetic field and applied temperature. Take for example performing an M v H measurement at a constant temperature and a demagnetized sample. The Initial Magnetization curve is different than the top hysteresis curve in quadrant 1 and the bottom hysteresis curve also in quadrant 1. Because:

Demagnetized State of material means equal pos. polarized and - polarized grains.

Start Initial Curve: Demag state -> increasing applied pos. H -> increasing pos. M

End Initial Curve: Hysteresis curve slope approaching zero -> M saturated in pos. polarity direction.

Next, start in fully saturated pos. magnetization state, reduce pos. H to zero, then from H = 0 increase negative polarity of H to reach magnetic saturation in negative polarity direction.

Finally, now in fully saturated neg. magnetization state, reduce neg. H to zero, then from H = 0, increase pos. polarity of H to reach magnetic saturation in pos. polarity dir. a second time.

When it comes to magnetic hysteresis, history differentiates initial magnetization curve from the top and bottom arms.

When you perform a M vs. T, you are holding the H field constant and changing temperature. This is a much different history than M vs. H.

But, lets say your material magnetically saturates during hysteresis at 200 K at H = 1,000 Oe. Then you should see your M vs. T (FC and ZFC) hit the magnetic saturation value at 200K at an H = 1,000 Oe too. Unless something interesting is going on in your material.

But if you use too high of an applied magnetic field (H) during M v. T you might reduce the magnitude of any magnetic phase transitions you might be looking for.

So, typically M v T and M v H curves exist to measuring different properties of magnetism in a material. And they are not typically "evenly compared"

But lets say you notice a magnetic phase transition at 120K (like Verwey transition in Fe3O4), you can perform a M v H at 100K and another at 140K to see the magnetic behavior before and after the transition to confirm what you expect is happening.

I wrote a lot. I hope I did not confuse you. Good luck.

Best,

Dr. Jason R. Morales

Sudhanshu Dwivedi. Also:

M v T - It looks like you might have two magnetic transitions at 180K, 360K. Is this FC or ZFC curve?

M v H - CrO2 looks like it is behaving superparamagnetically. Maybe indicating grain/crystallite size below the single domain size limit in your material.