There are several issues here:

1. before starting measurements please calibrate properly VSM system using the reference sample (Ni).

2. position the samples in the same place with the reference sample, if the sample is decentralize you can get a shift of the hysteresis curve.

3. Do not use larger samples greater than those recommended by the manufacturer's VSM.

4. Takes several points in the range -0.5 +0.5 kOe kOe in order to correctly read Hc,

5. constant time per point higher.

6. Find the mass or volume of your sample magnetic component (magnetic moment in emu is not relevant at all, to compare samples between them M must be expressed in emu / g or emu / cm3)

7. really to see if you really must superparamagnetic behavior further measurements ZFC and FC

In general hard magnetic materials exhibit widened H-loop and soft magnetic materials shows narrow H-loop , also there will be presence of hysteresis on ferro, ferri magnetic system with increased saturation magnetization [Ms] , in this case the sample doesnt exhibit hysteresis and it seems to be "Superparamagnetic" material ......... in general these materials will have single domain particles ....you can see that it doesn't exhibit any change either on reversing the field in reverse side .......... you can check the below weblinks for more details...........all the best  

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/hyst.html

http://en.wikipedia.org/wiki/Superparamagnetism

http://mappingignorance.org/2014/03/05/superparamagnetic-nanoparticles-and-the-separation-problem/

Dear Rozita,

Your material is a soft magnet. Saturation magnetization in your material is 23 emu.

But, I should tell you that there is a problem in your result. Because, in hysteresis curve, the origin of the coordinate axes should be in center of your curve. In this condition, you can determine the Hc and Br and ...

please see it in below article.

With Bests

http://www.sciencedirect.com/science/article/pii/S0921510714002013

Another possibility - besides a measurement problem - is the idea that we see the hysteresis loop of an exchange bias system after field cooling. These systems can show horizontal as well as vertical shifts. Rozita, can you tell us more about your system under examination and the measurement conditions (temperature, possible field / zero field cooling etc.)?

As your material is @ nanoscale size, the magnetic behavior expected when measured at RT, refers to what is known as superparamagnetic phase. The characteristics of it is similar to exactly what your result is about. The value of your coercivity might be misleading. Make sure the sensitivity factor while measuring nanoparticle sample must be high. You may need to increase the no. of points in order to get much accurate results. From another angle; You may be in need to compare your value of Ms with bulky sample to see if there is an enhancement achieved. Moreover, to be really definite of whether your sample exist in its nanoscale or not, you might be required to run FC/ZFC measurement and then you can observe the magnetic transition very clearly.

You may refer to following articles for further clarification;

1- http://www.sciencedirect.com/science/article/pii/S0011227512001403

2- http://www.sciencedirect.com/science/article/pii/S0266353814000918

Thanks a lot for the helpful comments. I need to analysis 20 samples in my paper and I need to know to how analyse VSM row data. Is there any guide instruction to show me that what should I do step by step?

For your measurement I would recommend to measure far more data points in the range from -0.5 kG to 0.5 kG to get a more precise idea about coercivity and remanence. In addition I would measure minor loops to learn something about the magnetization mechanism. In case your material does not exhibit the exchange bias effect, you need to calibrate the VSM setup better, so that the hysteresis loop is centered around the orgin.

There are several issues here:

1. before starting measurements please calibrate properly VSM system using the reference sample (Ni).

2. position the samples in the same place with the reference sample, if the sample is decentralize you can get a shift of the hysteresis curve.

3. Do not use larger samples greater than those recommended by the manufacturer's VSM.

4. Takes several points in the range -0.5 +0.5 kOe kOe in order to correctly read Hc,

5. constant time per point higher.

6. Find the mass or volume of your sample magnetic component (magnetic moment in emu is not relevant at all, to compare samples between them M must be expressed in emu / g or emu / cm3)

7. really to see if you really must superparamagnetic behavior further measurements ZFC and FC

Dear Rozita,

for giving more advice, it might be helpful if you shared what the information is that you want to retrieve from your data. It is easier then to recommend procedures for making the proper evaluations.

Your MH plot looking like ferrimagnetism and moreover you can analysis superparamagnetic sate in MT plot at low temperature. Because most of magnetic nanoparticles will exhbit superparamagnetic state between curie temperature to neel temperature region.

Your graph looks that your material is superparamagnetic with very low remanence and coercivity.

Also if you have not normalize the graph so normalize it as emu/gm if nanoparticles and emu/cc if thin films.

Anybody plz help me to analyse VSM data

Dear Thakur, pls provide me the details of what your sample is and its magnetic behavior u obtained using VSM? I will provide you a point by point clear analysis. Regards

How to convert field data from G to H

Dear Shaveta,

Field intensity (H) -> oersted (Oe)

Magnetization (M) -> gauss [3] (G)

They are technically units for incommensurate quantities, but in practice this is often just a technicality. The magnetic field that makes sense (BB) is measured in teslas (SI) or gauss (CGS), and the magnetic field that people spoke about 100 years ago (HH) is measured in amps per meter (SI, also equivalent to a number of other things) or oersteds (CGS).

To go between the two unit systems, we have

1 G = 10-4 T

1 Oe = (1000/4*Pi) A/m

1 Oe corresponds to 10−4 T

https://www.qdusa.com/sitedocs/UnitsChart.pdf