Microscopic experimental evidence of sublattice decoupling and negative magnetization in a spinel ferrite

We have observed the phenomenon of negative magnetization in spinel ferrites, CoCr2-xFexO4. The x = 0.15 compound lies in the interesting region of the composition (Fe) driven magnetic phase diagram as it shows two magnetic ordering temperatures along with a negative magnetization behavior. We have given a microscopic experimental proof of magnetic sublattice decoupling and temperature-induced negative magnetization using the neutron diffraction technique. The present study supports the Belov's hypothesis of a weak magnetic sublattice for an explanation of negative magnetization, where the weak octahedral sublattice deviates from the Brillouin function type behavior of sublattice magnetization as envisioned by Neel in his theory of ferrimagnetism. A physics concept for a possible application of such a negative magnetization phenomenon in spin transfer torque based magnetic random access memory has been outlined. Published by AIP Publishing.