High temperature EPR study of the M3Fe4V6O24 (M = Cu, Zn, Mg and Mn)

Electron paramagnetic resonance (EPR) spectra of M Fe (M = Cu, Zn, Mg and Mn) compounds in high temperature range (293 K to 493 K) have been investigated. The role of magnetic (Cu, Mn) and non-magnetic (Zn, Mg) ions in M Fe structure in formation of magnetic resonance spectra was studied. Temperature dependence of EPR parameters: resonance field, linewidth and integrated intensity were examined. Similarities and differences in temperature behavior of these parameters has been discussed in terms of different relaxation mechanisms and magnetic interactions in the spin systems. An important role of additional magnetic ions (M = Mn or Cu) in the M Fe structure has been identified and its consequences considered.