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Post by badsha on Feb 7, 2023 8:54:03 GMT -5
How to calibrate the thin film sample by varying x and y distance? I want to use my own .8* .8 cm2 thin film sample to calibrate whose magnetization is low( around 1200 emu/cc). I am not getting symmetric M- H loop. I put the sample first in the geoometric center then I vary the x distance so that moment is minimum then I vary y distance. And i choose the y point where the moment is maximum. Can you please suggest me what's the procedure to calibrate the sample having low magnetization?
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Post by Lake Shore Cosmin on Feb 7, 2023 12:59:20 GMT -5
Hello, I guess you are referring to saddling or centering the sample and not actually calibrating the moment gain of the magnetometer. You can saddle the sample using a sample with same dimensions but larger magnetic moment, such as a piece of credit card stripe and then substitute with your low moment sample.
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Post by badsha on Feb 8, 2023 4:29:46 GMT -5
Thank you. Yesh, I am talking about saddling
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Post by badsha on Feb 8, 2023 6:09:01 GMT -5
Hi.
Could you plz tell that how should I vary the x and y knobs of VSM for this calibration?
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Post by Lake Shore Cosmin on Feb 9, 2023 14:32:24 GMT -5
For more guidance on this, see Section 4.3.3. in the 7400-S Series VSM user manual, which shows moment vs. position on all three (X-Y-Z) axes. It explains how much moment is affected by a sample being off-center.
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Post by Lake Shore Cosmin on Feb 9, 2023 14:35:35 GMT -5
Sample Saddling
The sample should be positioned at the geometric center of the pickup coils, a procedure known as "saddling." On a standard electromagnet system, the saddle point is found by finding the local extrema of the moment signal in the x, y, and z directions. Generally, the x (left to right) position should be a local minimum in the moment signal (or its absolute value, to be precise). The y (front to back) position is a local maximum, and the z (up and down) position can be either a maximum or a shallow minimum between two maxima, depending on the separation between the coils. For very weak samples, it is a good idea to saddle using a strong sample (such as a saturated nickel standard), with the same geometry as the weak sample, attached in the same manner as the weak sample to be tested.
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