Some features of Mn2+ EPR spectra in cubic nano-ZnS.

Four ZnS nanopowders containing an uncontrolled impurity of manganese were studied using EPR technique. The powders with the average sizes (6...8 nm) were synthesized by either joint or sequential decomposition of diethyldithiocarbamate complexes of zinc and europium in high-boiling solvents at various temperatures. All samples demonstrated the EPR signal that is not typical for ZnS powders with µm-sized particles. Computer simulation showed that EPR spectra of all the samples could be fitted by two components. The first component with g = 2.0022 ± 0.0002, (63.5 0.5) 10-4 cm-1 A = - ± × , 0 4 1 4 3.5 10 cm- - b × was assigned to Mn2+ ions in the cubic surrounding, Mn(C). The parameters of the second component were g = 2.0022 ± 0.0002, (63.5 0.5) 10-4cm-1 A = - ± × , 0 () 4 1 2 36 1 10 cm- - b = - ± ×; this component was attributed to Mn2+ ions associated with a planar lattice defect (stacking fault), Mn2+(D). The ratio of centers amounts Mn2+(C)/Mn2+(D) for the samples studied was 2.1/1 (in the samples 1 and 4) and 1.7/1 (in the samples 2 and 3), respectively. EPR of Mn2+ ions was shown to be an effective method for detecting planar lattice defects in ZnS nanoparticles. [ABSTRACT FROM AUTHOR]