EPR - electron paramagnetic resonance. Spectroscopic technique that relies on the detection of microwave-induced transitions between the split sublevels of a paramagnetic defect. Generally, an external (quasi-constant, slowly swept) magnetic field removes the spin degeneracy of the system under study. The resonant transitions are detected via absorption of microwaves. Usually, ground states of defects are detected.

ODEPR - optically detected electron paramagnetic resonance. Variation of the classical EPR experiment by which the detection of resonant absorption in the microwave field is replaced by the detection of resonant changes in the photoluminescence (PL-ODEPR) or optical absorption (MCDA-ODEPR) associated with the defect. Several orders of magnitude in sensitivity are commonly gained over the classical detection of EPR.

ODMR - optically detected magnetic resonance techniques (see ODEPR).

ENDOR - electron-nuclear double resonance. Spectroscopic technique complementary to EPR. When the EPR transition of a paramagnetic defect system under investigation is broadened by hyperfine interactions, resonant transitions within the nuclear sublevels involved may be generated and detected using an additional radiofrequency field. Identification of the atomic species involved can be thus made. It is often possible to map out the lattice environment of the defect.

OD-ENDOR - optically detected electron-nuclear double resonance (see ENDOR and ODEPR).

MCDA - magnetic circular dichroism in absorption. Spectroscopic technique detecting the difference in absorbtion between left- and right- circularly polarised light. The difference arises from the Zeeman population difference between the split sublevels of the ground state of a paramagnetic defect. At magnetic resonance, the population difference is canceled and a magnetic resonance signal is detected (see ODEPR).

IN-SITU - used here in conjunction with electron irradiation. Stands for "investigation of as-induced defects". It is performed by continuously keeping the sample at low temperatures during irradiation and subsequent spectroscopic investigation to prevent the newly-generated defects from migrating and forming complexes with other defects.