Figure 5

ODMR spectra as a function of magnetic field direction. (a) Sample S5 (at room temperature 293 K) - evolution of the ODMR spectra when the magnetic field (\(\mathrm{B}=50\mbox{ G}\)) is gradually tilted between the [100] and [110] and between the [110] and [111] directions. Symbols I, IIa, IIb, label specific ODMR resonances which change their frequency as a function of the angle. (b) The related \(T_{1}^{-1}\) relaxation rates vs. the angle between B and the crystallographic axes for three groups of ODMR resonances (marked by different colors). Dash/dot lines in panels (a) and (b) are used for guiding the eye, while the vertical dotted lines indicate the crystallographic directions.