Development of an X-band magnetic resonance force microscope

Abstract We have developed an X-band magnetic resonance force microscope (MRFM), and demonstrated the first measurements on a few nanogram 1,1-diphenyl-2-picrylhydrazyl (DPPH) sample. We have successfully observed the MRFM signal with some structure at 9.88 GHz at room temperature. The force detection sensitivity of our MRFM system is ∼10 −15 N, which corresponds to the magnetic force of ∼10 6 resonant electron spins under the magnetic field gradient of 100 T/m. The ESR signal sensitivity of our MRFM system is 10 3 –10 4 times higher than the commercial X-band ESR instrument.