KIT FOR STUDYING SUPERCONDUCTIVITY

KIT FOR STUDYING SUPERCONDUCTIVITY KIT OF MAGNETIC SUSCEPTIBILITY When a substance becomes superconductive, its magnetic susceptibility undergoes a sharp variation. Two kits have been designed to demonstrate this phenomenon
: one uses bismuth and the other yttrium.
The kit using bismuth has two separated superconductive
crystalline phases: one with critical temperature of
approximately 85 K and the other with critical temperature of
110 K.
The kit using yttrium has only one phase and the critical
temperature is of approximately 88 K.
When a material is in the state of superconduction, it merely
becomes diamagnetic. As diamagnetism increases, the
inductance of the material becomes lower.
In the case of bismuth, when temperature falls, induction
suddenly passes to approximately 110 K. Now the internal
part of the material including crystalline phase becomes
superconductive. Then, from 105°K to 90°K, there is a decrease
because the material remaining in crystalline phase becomes
superconductive. From 90°K to 85°K inductance undergoes a
further sudden reduction because other parts of the material
become superconductive.
Yttrium’s behaviour is similar, but in this case there is only one
phase around 88°K.
Each kit includes a tablet of bismuth or of yttrium, a resistor
of 100 W, a susceptibility sensor, small magnets, pliers and an
experimental handbook.
SAND CRYOSTAT
This system enables to obtain a more gradual rise of
temperature during the test. This means that there is enough
time to represent the measured data accurately.
ACCESSORIES
• function generator
• sand cryostat
• AC ammeter
• AC voltmeter
• DC voltmeter