Spin-Lattice and Spin-Spin Relaxation Times of Water Doped with Paramagnetic Ions [NMR]

Chelsey Dorow and Chris Storino

University of Minnesota

Methods of Experimental Physics Spring 2012

Abstract

Nuclear magnetic resonance spectroscopy was used to study microscopic magnetic interactions between the hydrogen nuclei and local molecules of water samples with different concentrations of CuSO4. The energy exchange and mechanics of these magnetic interactions are described with two material-specific relaxation times: spin-lattice and spin-spin. The spin-lattice and spin-spin relaxation times for each concentration were measured to observe the effect of these paramagnetic ions on the water molecules; higher concentrations increased the rate of energy exchange through dipolar relaxation, resulting in a decrease of relaxation times. We used pulsed nuclear magnetic resonance with radio frequency magnetic field pulses and compared our results to values found in literature. The measured T1 and T2 values decreased monotonically with increasing concentrations of CuSO4, however, T2 values deviated farther from expected literature values.