Hello.
I am from a completely different field (biochemistry), but used the SQUID to measure a possible magnetic moment of my biological samples.
I measured a BLANK (glycerol) and my sample (see attachments). Can someone help me with the following questions:
1.) The blank and the sample seem to show a difference, but what does this result tell me scientifically?
2.) What would be the proper way for further data treatment/preparation? I have seen that most SQUID results are given in emu/g or emu/cm^3 ?
I am hoping to find some help here.
1. First, it is necessary to check the sign of magnetization and check if there is no inversion of this sign into positive and negative fields.
2. The Blank and the sample curves seem to show a slight difference. To confirm this, make the difference between the two curves and compare it to the sensitivity of your SQUID, before looking for explanations!
3. M(emu/cm^3) = Density (g/cm^3) *^M(emu/g)?
4. If the curves are correct, the Blank and the samples would be diamagnetic
Dear Alexander Pekarsky,
I would suggest you the following points
1. Please consider to subtract M(H) of the sample with M(H) of the BLANK. I guess there would be a ferromagnetism or paramagnetism. Do further interpretation by looking references discussing on magnetism.
2. Please check the unit of M in the instrument guide.
3. Please first check the data validity. Smooth curves might give an easier way to analyze.
May this helps
Best regards,
S. Muhammady
Thank you Mr. Shibghatullah Muhammady and Mr. Mohamed El Hafidi for you input.
@ Mr. Shibghatullah Muhammady please see the attachement:
I first formed emu/g by dividing the signal with the actual sample mass. Then I subtracted the emu/g of the blank from the emu/g of the sample for the respective fields. From my point of perspective, it seems that a small ferromagnetic behaviour of the sample could be present.
The magnetic susceptibility Khi of glycerol [which is a measure of how much a material will become magnetized in an applied magnetic field. (Mathematically, Khi = the ratio of magnetization M (magnetic moment per unit volume) to the applied magnetizing field intensity H : Khi =M/H)] is negative , Khi = -57.06·10−6 cm3/mol confirming that glycerol is diamagnetic.
In your case, the proper signal of your sample is Mspec=Msample-MBlank grows positively with the field, which would mean that the sample would be paramagnetic or weakly ferromagnetic.
But the major problem in your result is that the curves have many disparities and fluctuations.
So it would have to:
-verify your experimental data and sensitivity of your SQUID
-work at a constant temperature
- repeat the manipulation at a lower temperature (if possible), the signal would be more significant
Good luck
Hi Alex,
Your M(H) loop has a diamagnetic component in it and as a result it had that negative slope. Once the diamagnetic component is being taken off from your M(H) loop you should get a new plot which is similar to the new graph you obtained. Additionally to smooth your graph you can do a 3-point averaging and then re-plot it.
Best
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