POSITRON-ANNIHILATION STUDIES IN BINARY SOLID-SOLUTIONS OF METAL BETA-DIKETONATES, USING LIFETIME AND DOPPLER BROADENING SPECTROSCOPIES

Positron annihilation lifetime (LS) and Doppler broadening annihilatio n radiation lineshape (DBARL) spectroscopies measurements were perform ed in several binary solid solutions of the general formula M(1-x)G(x) L3, where M = Al (III) , Ga (III) , or In(III), as matrix; G = Cr(III) , Mn(III), Fe(III), Co(III), Ru(III), Rh(III), and Ir(III), as guest m olecules, L = acetylacetone (acac) or dipivaloylmethane (dpm), and X = guest molecule mole fraction. The studied systems can be classified i n two groups: the first one presenting only inhibition of positronium formation and the second one presenting inhibition and quenching effec ts. The inhibition and quenching constants were determined.