Low Field Electrically Detected Magnetic Resonance

Open Access
Author:
Acquaviva, Joseph
Area of Honors:
Engineering Science
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Patrick M Lenahan, Thesis Supervisor
  • Jun Huang, Honors Advisor
  • Judith A Todd, Faculty Reader
Keywords:
  • EDMR
  • magnetic resonance
  • SiC
Abstract:
Very little literature exists regarding electrically detected magnetic resonance (EDMR) at low fields. EDMR at low fields holds exciting possibilities for device characterization as there is relatively little loss of signal strength at low fields, where there is a very large loss in sensitivity in conventional magnetic resonance at low fields. Furthermore, at least in principle, for signals primarily broadened by spin-orbit coupling, there might actually be significant signal to noise advantages in low field measurements. We tested SiC MOSFETs under magnetic fields ranging from 0 to 50 gauss while exposing them to RF power. The goal is observe spin dependent change in the current through the device which is consistent with the Planck-Einstein equation. After discussing the background theory, we gave a detailed description of the low field EDMR rig used for these experiments, highlighted the component subsystems and stated ways to check each one. Despite the sound theoretical basis for low field EDMR, and apparent proper operation of the individual subsystems, we were unable to obtain an EDMR signal using the low field rig. We highlight an example test which first seemed promising, but failed under scrutiny and explain why. We make note of several of the problems we encountered during the course of experimenting, as well as the steps we took to fix them. We attempt to explain several possible reasons for the inability to obtain an EDMR signal and finally we end with a complete list of steps that must be taken, for in the future, when we do observe EDMR with the current setup.