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 jtm-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, A = (-63.5 +/- 0.5).10(-4)cm(-1), b(4)(0) >= 3.5.10(-4)cm(-1) was assigned to Mn2+ ions in the cubic surrounding, Mn(C). The parameters of the second component were g = 2.0022 +/- 0.0002, A = ( 63.5 +/- 0.5).10(-4)cm(-1), b(2)(0) = (-36 +/-).10(-4)cm(-1); 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.