Magnetic Susceptibiliy Introduction

One of our condensed matter experiments.

Goal: Discern the low temperature magnetic behavior of a varienty of different materials.

Dipole in a magnetic field => torque on the magnet to align it with the direction of the magnetic field. Uniform magnetic field.

In a non-uniform field, there with additionally be a force that pulls it into the higher field region. Non-uniform field (or gradient) results is force as well as torque.

Water cooled electro magnetic, measure the force the reading on the balance. Measured Weight could increase/ or decrease (diamagnetic / paramagnetic)

Physics:

• unpaired electrons => net spin (paramagnetic, several classes)
• does not have unpaired => no net spin diamagnetic

Competing with thermal energy, spoils the net spin.

Goal is to determine which energy of interaction is dominant

You will do it at room temperature, then with LN2 you will do it at (77k )