Role of the antiferromagnetic bulk spins in exchange bias

This Critical Focused Issue presents a brief review of experiments and models which describe the origin of exchange bias in epitaxial or textured ferromagnetic/antiferromagnetic bilayers. Evidence is presented which clearly indicates that inner, uncompensated, pinned moments in the bulk of the antiferromagnet (AFM) play a very important role in setting the magnitude of the exchange bias. A critical evaluation of the extensive literature in the field indicates that it is useful to think of this bulk, pinned uncompensated moments as a new type of a ferromagnet which has a low total moment, an ordering temperature given by the AFM Neel temperature, with parallel aligned moments randomly distributed on the regular AFM lattice. (C) 2016 Elsevier B.V. All rights reserved.