Figure 2. B-field direction dependence.

Echo amplitude at 300 mT as a function of separation time for different in-plane magnetic field directions θ, with 0° corresponding to the [110] direction. Curves are offset for clarity. At 45°, parallel to the crystallographic [100] axis, the coherence time is enhanced as quadrupolar couplings are suppressed. When rotating the field, a g-factor anisotropy leads to oscillations, associated with the three different nuclear Larmor frequencies. A semi-classical model (solid line) is used to fit the data (dots).