Electron Paramagnetic Resonance of Mn²⁺ Ions in Nanosized Zinc Sulfide with a Planar Lattice Fault

We have studied the EPR of Mn²⁺ ions in three samples of cubic nano-ZnS made by different technologies and having different nanoparticle sizes. Manganese occurs in the samples as an uncontrolled impurity. The EPR spectra can be described by two components: the spectrum of the Mn²⁺ in a cubic environment (Mn²⁺(C)) with parameters g = 2.0022 ± 0.0002, A = (–63.5 ± 0.5)·10^–4 cm^–1, 0 b4 ≥ 3.5·10^–4 cm^–1; and the spectrum of the Mn²⁺ ion associated with a planar lattice stacking fault (Mn²⁺ (F)), with parameters g = 2.0022 ± 0.0002, A = (–63.5 ± 0.5)·10^–4 cm^–1, $b_2^0$ = (–36 ± 1)·10^–4 cm^–1. The ratio of the number of centers Mn²⁺(C)/Mn²⁺(F) is 2.1:1 for sample 1 and 1.7:1 for samples 2 and 3. Planar stacking faults are typical lattice faults for cubic nano-ZnS. EPR of the Mn²⁺ ions lets us monitor the presence of these ions.