VSM program didn't work well so the data files were damaged, so i uploaded the data table instead, sorry for the inconvenience.
I cured Ecoflex-0020 with Neodymium magnet powder, and aligned magnet powder within it with external magnetic field.
And to figure out magnetic characteristics of my samples, the vsm data seemed quite strange; the graph isn't symmetric, rather, it looks like it moved to rightward.
Hc upward part : 1912.388 Oe
Hc downward part: -265.853 Oe
My sample is quite thick and soft, so i guessed maybe since my samples are soft elastomer, under large magnetic field it might had distorted and the result changed like that, however, even after i folded my sample tightly with teflon tapes, several layers, it still gave me similar result.
Would you give me an advice what to do to correct my data?
Thank you in advance.
Dear Junseok Lee,
Apparently, due to the failure of the data processing program, the new results were counted from some point from the remaining old data. Try shifting the chart by 823.267 Oe to the left and 2.209 emu up.
If you do not have a loop image and a data set, then Mr is difficult to determine, because in the specific case you have given, the values +Mr and –Mr must be recorded at H=823.267 Oe. And it most likely lies between 8.712 and 13.385 emu.
Maybe everything is quite correct. The mystery comes from neodymium magnet powder. This material is well known to be magnetically hard. In this case obtaining symmetrical hysteresis loop is only possible when the range of external field is high enough, probably exceeding 25 000 Oe. Did you try to investigate the similar sample but obtained without earlier alignment of neodymium powder?
What was the maximum field value in the VSM? What shape was the sample? And how is the sample (taking into account its geometry) it was oriented with the direction of the field of the electromagnet (the true field acting on the sample depends on this)? If the field was not sufficient for complete remagnetization of the sample, then a partial hysteresis loop is observed, and an assumption by prof. Gutovsky is is a good explanation. If the field was high enough, the loop should be symmetrical.
@Morchenko i appreciate for your sincere advices! The maximum field was 2 Tesla, and i cut my sample to 6mm x 6mm x 2mm cuboid like shape. Field direction was out of plane of my samples. I will find way to increase external field and measure samples again, thanks a lot!
Dear Junseok Lee,
Based on the context of the discussion and what you have said additionally, you may have slightly missed the necessary fields required for complete remagnetization and did not reach the saturation state, so in fact, you observed partial hysteresis loops. At the same time, depending on the previous background, you could start the cycle from different residual states of the sample remaining from previous manipulations or measurements. Therefore, you could get more or less symmetrical pictures. I understand that you are trying to reduce the gap between the poles of the magnet to get the largest field value. However, to facilitate the remagnetization, try to use a thinner sample, but apply the field in its plane (in the direction of its longest axis), and not along the normal to it. Perhaps you should cut out the piece of the sample in the form of a small long rod and apply the field along its axis.
And by the way, we can also say about the data you have given that the numerical values of all the main magnetic parameters of your sample for the full (major) hysteresis loop are likely to be higher than on the symmetrized partial (minor) loop.
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