Modification of existing closed cycle refrigerator for AC susceptibilty measurement

Abstract

An experimental set up for cryocooler based ac susceptometer is designed. Hylum is chosen the former over which, the copper windings are done. The design consists of primary coil, secondary coils and a sample holder. Ac susceptibility is most conveniently measured using the mutual inductance principle. Copper wire (150micron) winding is done on the primary and the secondary coils. The secondary coil is connected in series opposition i.e. if one wound is clockwise, the other is anticlockwise. A Pt100 temperature sensor is put in close proximity with the sample, in order to record the sample temperature accurately. La0.83Sr0.17MnO3 sample is prepared as test sample for measuring the susceptibility.