EPR STUDY OF THE AG6S3O4 COMPOUND PREPARED BY 2 METHODS

The temperature dependence of the EPR spectra of the recently discover ed Ag6S3O4 phase in the Ag-O-S system prepared by two methods, the kno wn method of co-precipitation from aqueous solution and a new method d epending on the interaction of Ag2S and Ag2SO4 solid reagents, has bee n investigated. No EPR spectra were observed at room temperature, whil e at liquid helium temperature a number of EPR spectra have been recor ded, which disappeared upon increasing temperature up to liquid nitrog en temperature. The sample obtained by the co-precipitation method rev ealed an intense, rich EPR spectrum that has been tentatively interpre ted assuming the presence of at least two different Ag2+ ion complexes , one monomer resulting in an intense anisotropic, rhombic EPR powder pattern with g(1) = 1.93(1), g(2) = 2.025(3), g(3) = 2.094(5), hyperfi ne constants A(1) = A(2) = 60(5).10(-4) cm(-1), A(3) = 90(5).10(-4) cm (-1) and one dimer EPR pattern presumably involving a pair of Ag2+ ion s with internuclear separation of 4.3 Angstrom. However, the presence of larger clusters could not be excluded. On the other hand, the sampl e obtained by a solid state reaction method has given rise to two rath er weak EPR lines centered at g(eff) = 2.105(3) acid g(eff) = 4.213(3) , respectively.