The nuclear magnetic relaxation characteristics of formations will change if there are paramagnetic materials in the formations.

Magnetic relaxor ferroelectric materials (MRF) are compounds in which the relaxor ferroelectricity and ferromagnetic (antiferromagnetic) order coexist simultaneously in certain temperature range.

These experiments illustrate that paramagnetic ions imbibed in rock brine can shorten the relaxation time of the water protons, but can't effect the relaxation time of oil protons.