Which substances are feebly magnetised in the opposite direction of magnetic field, when placed in strong magnetic field?

Diamagnetic materials have a weak and temporary response to an applied magnetic field. When subjected to a strong external magnetic field, the atomic or molecular currents induced within diamagnetic materials produce a magnetic field that opposes the external field. This results in the material being weakly magnetized in the opposite direction to the applied field.

Examples of diamagnetic materials include:-

These materials exhibit diamagnetic behaviour due to the paired electrons in their atomic or molecular orbitals, which generate opposing magnetic moments when subjected to an external magnetic field.