How do diamagnetic materials respond to a nonuniform magnetic field?

In the context of electromagnetism, diamagnetic materials respond to a nonuniform magnetic field by experiencing a force that pushes them toward regions of decreasing field strength.1

This behavior occurs because diamagnetic materials possess a negative magnetic susceptibility. When placed in an external magnetic field, these materials develop an induced magnetic moment that opposes the applied field, in accordance with Lenz’s law.213

Mathematically, the force $F$ exerted on a sample of volume $V$ in a magnetic field $H$ that increases in the $x$-direction is given by:
$$F=\chi {\mu }_{0}VH\left(\frac{dH}{dx}\right)$$
Because the susceptibility $\chi$ is negative for diamagnetic substances, the resulting force is directed toward the area where the magnetic field strength is lower. This is why diamagnetic materials are characterized as being repelled by the poles of a magnet.1