Metallic Multilayers and Epitaxy

Abstract

Figure 2. The dependence of the superconducting transition temperature of NbN films grown on three different types of substrates plotted as a function of substrate temperature during deposition. From the paper "Epitaxial Niobium Nitride/Insulator Layered Structures" by J. Talvacchio, J.R. Gavaler, and A.1. Braginski. 18,----,------,----r---..., spacer layer induces order. When spin motions within one film are excited, long range fluctuating dipolar fields are generated, exciting spin motions in neighboring films. Under these conditions, a coherent ground state is obtained for the entire structure. For alternating ferromagnetic and antiferromagnetic films, the application of a magnetic field induces spin reorientation transitions. He values were shown to vary inversely with the member of lattice planes present in each ferromagnetic film, thus suggesting the ability to tailor the structure. Incident electromagnetic energy can excite a soliton response, transmitting the impinging wave through the structure in a resonant mode. This phenomenon can result in a reflecting structure becoming specifically transparent to radiation. Recent studies suggested that increasing the incident power near the resonance level may excite the electron spin system enough to induce a non-linear magnetic susceptability to the applied field. The second session in this symposia was devoted to superconducting multilayer systems fabricated by advanced sputtering techniques. Those presentations covered amorphous metallic multilayers in fractal, quasi periodic and random layering sequences. Another study reported on the first 60 40 20 oL_......._....L._--'-_--l"-_"-----' o