Theory of ortho ⤥ parahydrogen conversion on paramagnetic and antiferromagnetic surfaces

An attempt is made to establish a theory to explain the many facet experimental results of o ⤥ pH ₂ conversion over paramagnetic and antiferromagnetic surfaces in the absence or presence of an externally applied field. The basis of the treatment invokes various nuclear relaxation mechanisms including that for nuclei of an antiferromagnetic above T_N, and a postulate that there might exist pocketful regions in an antiferromagnetic which exhibits ferromagnetic ordering below T_N.