Concentration dependent spin-lattice relaxation in n-type silicon
Affiliation:
1. São Carlos Engineering School, University of São Paulo, São Carlos, Brazil;2. Department of Mechanical Engineering, Federal University of São João del-Rei, São João del-Rei, Brazil;3. Department of Production Engineering, Federal University of São Carlos, Sorocaba, Brazil;4. Araguaia Engineering Institute, Federal University of Southern and Southeastern Pará, Santana do Araguaia, Brazil;5. Department of Structural Engineering, University of São Paulo, São Carlos, Brazil;6. Department of Civil Engineering, Federal University of São Carlos, São Carlos, Brazil;1. Max Planck Institute for Metabolism Research, Cologne, Germany;2. Department of Neurology, University Hospital of Cologne, Cologne, Germany;3. Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA;4. Cologne Cluster of Excellence in Cellular Stress and Aging-Associated Disease (CECAD), Cologne, Germany;5. Department I of Internal Medicine, University Hospital of Cologne, Cologne, Germany;6. Center for Endocrinology, Diabetes and Preventive Medicine (CEPD), University Hospital of Cologne, Cologne, Germany;7. Department of Psychology, Yale University, New Haven, CT, USA;8. Modern Diet and Physiology Research Center, New Haven, CT, USA;9. Clinical Trials Centre Cologne (ZKS Köln), University of Cologne, Cologne, Germany;10. Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
Abstract:
Spin-lattice relaxation mechanisms for the donor electrons in uncompensated silicon are presented. Major isolated spins transfer their excitation energies via the spin-diffusion process to the fast-relaxing centers. For lightly doped samples. Nd ≲ 1016cm3, exchange-coupled donor pairs act as the fast-relaxing centers. Theory provides the correct order of magnitude for the relaxation rate 1Ts role=presentation style=font-size: 90%; display: inline-block; position: relative;>. However, the calculated relaxation rate 1Ts role=presentation style=font-size: 90%; display: inline-block; position: relative;>, for this process is field independent, while the observed rate shows a weak field dependence.For more heavily doped samples, Nd > 1016/cm3, the relaxation rate can be explained by assuming the presence of a small concentration of neutral-ionized donor pairs. The relaxation process for these pairs is the resultant of two different mechanisms, a field dependent mechanism and a field independent one. The former depends strongly on the donor concentration and the latter shows relatively weak dependence on Nd.
