I am trying to measure the low temperature magnetic response of magnetic thin film material. However, both field-cooled and zero-field-cooled measurements produce noisy results which makes it difficult to infer the accurate value of the sample's blocking temperature and its magnetic phase behavior. Is this noise considered normal or is it because of the non-magnetic substrate that brings about negative values of magnetization especially in the field-cooled measurement? If so, then is there any way to correct the noisy behavior of both FC and ZFC measurements rather than regression trend line?
The magnetisation that you are measuring in a fc/zfc plot depends on the applied field. You can reduce it be increasing the applied field. However you must first measure the coercive field at low T. You must not use an applied field that is comparable or larger than the low T coercive field becasue this will blur the whole measurement out.
Dear Gehring, is there any specific low temperature value i am supposed to go for in order to obtain my sample's coercivity? In fact, i am confined in my experiment to LN2
You should measure it at the lowest temperature that you will reach in your fc/zfc experiemnt - in your case liquid N2
I think that increasing the applied magnetic field is a good idea to overcome this problem and of course H_co has to be known at low temperature. Then you can adjust your applied field after knowing H_co
Generally, every kind of measurement is more or less noisy. One way to go down with noise during magnetic measurements is to increase the measuring (integration, averaging) time. Up to 200 seconds per single readout are commonly reported.
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