Mechanical detection of nuclear spin relaxation in a micron-size crystal
Laboratoire des Solides Irradiés,
École Polytechnique, 91128 Palaiseau, France
2 Physics Department, Kazan State University, Kazan, 420008, Russia
Published online: 15 September 2000
A room temperature nuclear magnetic resonance force microscope (MRFM), fitted in a 1 tesla electromagnet, has been used to measure the nuclear spin relaxation of H in a micron-size (70 ng) crystal of ammonium sulfate. NMR sequences, combining both pulsed and continuous wave radio-frequency fields, have allowed us to measure mechanically T2 and T1, the transverse and longitudinal spin relaxation times. Because two spin species with different T1 values are measured in our 7 μm thick crystal, magnetic resonance imaging of their spatial distribution inside the sample section have been performed. To understand quantitatively the measured signal, we carefully study the influence of spin-lattice relaxation and non-adiabaticity of the continuous-wave sequence on the intensity and time dependence of the detected signal.
PACS: 07.79.Pk – Magnetic force microscopes / 76.60.-k – Nuclear magnetic resonance and relaxation / 87.61.Ff – Instrumentation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000