LOW-TEMPERATURE MAGNETIC-RESONANCE FORCE DETECTION

A low-temperature magnetic resonance force microscope (MRFM) has been built and a force sensitivity of 8 x 10(-17) N/root Hz has been achiev ed using a single-crystal silicon cantilever with a Q of 200 000 at 6 K. Nuclear magnetic resonance (NMR) of F-19 was measured via force det ection in a 1% Nd-doped CaF2 sample mounted on the cantilever. Cyclic adiabatic inversion of the F-19 nuclear spins was performed using a fr equency modulated radio frequency field at 100 MHz, resulting in an os cillatory magnetic force that excited the cantilever vibration. NMR fo rce signals were measured in the temperature range between 12 and 40 K . The MRFM technique was also used to measure some basic NMR propertie s such as spin-lattice relaxation time. (C) 1996 American Vacuum Socie ty.