Spin resonance of conduction electrons and EPR of localized moments in a low-dimensional organic conductor [Pd(dddt)(2)]Ag1.5Br3.5

The EPR spectra of a quasi-two-dimensional organic metal [Pd(dddt)(2)]Ag1.5 Br3.5 contain signals due to the spin resonance of conduction electrons (CE SR) and signals due to the localized magnetic moments of Ag2+. The system o f Ag2+ ions exhibits a strong indirect antiferromagnetic exchange interacti on characterized by the Weiss constant Theta = -280(25) K, which leads to m agnetic ordering at a temperature of T-0 = 70(10) K. The same temperature T -0 corresponds to a strong anomaly in the CESR linewidth. The observed anom aly in the CESR linewidth, as well as some features of the temperature depe ndence of conductivity in the system studied, are explained by the interact ion between conduction electrons and Ag2+ ions localized in the anion layer s (pi-d interaction) and by antiferromagnetic ordering of the spins of Ag2 magnetic ions. (C) 2000 MAIK "Nauka/Interperiodica".