Exchange couples of ferromagnetic thin films with antiferromagnetic oxide thin films and multilayers are investigated to elucidate the microscopic details of exchange anisotropy. These couples are of great technological interest because these oxides can serve as robust biasing elements for magnetoresistive read-heads. Surface treatment of particles to enhance their properties for recording media has long been practiced without a basic understanding of the origins of the increased anisotropy, since the surfaces of these nanoparticles are so difficult to characterize. Accordingly, we are studying much more easily characterized surface-treated thin films in order to provide fundamental understanding of this phenomenon, and to explore the use of surface-treated thin films for high density storage media. We are also studying, experimentally and theoretically, the influence of the lower coordination at the surfaces of ferromagnetic and antiferromagnetic systems on their magnetic properties.