Effect of He²⁺ Ion Irradiation on the Crystal Structure of Non-stoichiometric Sm_2+xZr_2-xO_7-x/2 (x = 0, 0.2, 0.4, 0.6)

In this paper, a series of non-stoichiometric Sm_2+xZr_2-xO_7-x/2 (x=0, 0.2, 0.4, 0.6) were synthesized by chemical co-precipitation method. He²⁺ ion irradiation experiments were carried out with irradiation energy of 500 KeV and irradiation flux of 5×10¹⁶ ions/cm². Effect of He²⁺ ion irradiation on the crystal structure was characterized by XRD, GIXRD, and Raman spectroscopy. The XRD patterns show that all the peaks shift to lower diffraction angles and the characteristic peaks of pyrochlore structure weaken after irradiation, which suggests an expansion of the lattice and the degeneration of pyrochlore structure. Moreover, the GIXRD patterns reveal the existence of an irradiated layer on the surface of the sample. (paper)