Phosphate Ca1/4Sr1/4Zr2(PO4)3 of the NaZr2(PO4)3 structure type: Synthesis of a dense ceramic material and its radiation testing

The powder of phosphate Ca1/4Sr1/4Zr2(PO4)(3) was synthesized by sol-gel processes in the presence of citric acid and ethylene glycol. Ceramic samples were prepared from this powder by Spark Plasma Sintering (SPS), their relative densities were found to be 99.5 +/- 0.3% after the isothermal treatment at 860 degrees C for 3 min. Sintered disc-shaped ceramic samples (d = 10 mm, h = 4 mm) were bombarded at 300k by 167 MeV Xe26+ ions with fluences ranging from 6 10(10) to 1 . 10(13) ions/cm(2). It was found that exposure to the highest fluence (10(13) ion/cm(2)) led to a complete amorphization of the irradiated layer. The observed phase transition is ascribed to the formation of amorphous latent tracks via dense electronic excitations. Post-radiation heat treatment revealed that the transformation from metamict to crystalline form took place after annealing at T= 200, 300, 400, 500, 600 and 800 degrees C and t = 3, 13, 11, 5, 17 and 15 h, respectively. (C) 2013 Elsevier B.V. All rights reserved.