Characterization of lead fluoride deposited within micropores of porous alumina

Abstract

PbF 2-Al 2O 3 composites were obtained by reaction between Pb(NO 3) 2 and NH 4F solutions within micropores of porous alumina pellets at room temperature and 50 °C. They were compared with PbF 2 powder prepared at room temperature and 50 °C in terms of morphology, phase stability and electrical conductivity. The deposit in the composites and powders prepared at room temperature consisted of α-PbF 2 and β-PbF 2 while those obtained at 50 °C mostly consisted of β-PbF 2. Regarding the composites fabricated at room temperature and 50 °C, the initially deposited β-PbF 2 grains showed virtually no preferred orientation, while the subsequently formed grains showed significant preferred orientation with the [hh0] direction parallel to the growing direction. The conductivity of the composite obtained at room temperature was lower than that obtained at 50 °C. This is probably caused by the formation of the α phase because it has a lower conductivity than the β phase. The composite obtained at 50 °C had a conductivity slightly lower than that of the pressed powder.