Phosphorus-containing cesium compounds of pollucite structure. Preparation of high-density ceramic and its radiation tests

Abstract

Multicomponent oxides of pollucite structure, containing Cs and Ba, were synthesized as powders and ceramics. Their chemical compositions, Cs[MgAl 0.5 P 1.5 O 6 ] and Cs 0.875 Ba 0.125 [Li 0.125 Zn 0.875 Al 0.5 P 1.5 O 6 ], were modeled on the basis of the known structural features, taking into account the principles of iso- and heterovalent isomorphism of cations. From powdered samples synthesized using sol-gel process, a ceramic was prepared by spark plasma sintering (SPS). The sintering time was 3–4 min in the temperature interval 600–850°C. The relative densities were 97 and 99%. To evaluate the radiation resistance of the ceramics, the samples were irradiated with 132 Xe 26+ ions ( E = 167 MeV) in the fluence interval from 6 × 10 10 to 1 × 10 13 cm −2 (ion flux density ∼10 9 s −1 cm −2 ). The amorphization took place at fluences of (1.2–1.3) × 10 12 cm −2 . This fact suggests the decisive role of the ion energy loss for ionization in the generation of radiation defects. Conditions were found for the transition of the metamict form into the crystalline form on heating.