Creating Pink Diamond at the Surface for Nanoscale Studies

Student: Derek Allman

Advisors: Chris Hammel and Vidya Bhallamudi (Arts and Sciences/Natural and Mathematical Sciences)

Abstract: Nitrogen-vacancy (NV) centers are impurities in the diamond lattice that make it appear pink. They have useful optical and magnetic resonance properties which makes them useful for studying spin related phenomenon in condensed matter and biological systems.  NV centers are generated by doping diamond with nitrogen and then irradiating the diamond with energetic particles, like electrons or alpha particles, in order to create vacancies within the lattice.  Following this, the diamond is annealed so that the nitrogen atoms and vacancies move adjacent to each other, thus creating NV centers.  NV diamond has a unique property that’s its magnetic resonance can be detected by measuring changes in photoluminescence (PL).  This is called optically detected magnetic resonance (ODMR).  This allows for magnetic fields to be measured optically using NV’s resonance.  Because of NV’s sharp resonance line even tiny fields from a single electron spin can be measured using the NV and in ambient conditions.  This makes NVs an especially useful tool for studying spin systems.   However, the NVs have to be close to the spins to achieve this kind of spin sensitivity.  It would be advantageous to have the NVs only at the surface so that only those influenced by the external spins are being measured.  However, creating a sheet of NV centers at this depth is difficult.  The purpose of this study is to learn how to create a thin layer of NV centers less than 100 nanometers below the surface.  First this will be investigated using finite element analysis in order to understand how the irradiation energy of particles and distribution profile of NV correlate.  Experimentally, diamond will be implanted with nitrogen using the energy determined to be optimal.  We will explore the relative benefits of irradiating the nitrogen implanted diamond with various sources, such as the electron beam of a scanning electron microscope (SEM) and other commercially available methods.  The NV diamond will characterized before and after irradiation using PL, Raman spectroscopy, and ODMR. 

Booth: 275