Application of Channeling Techniques and High Resolution Transmission Electron Microscopy to Ion-Beam Damaged Zircon

Abstract

AbstractZircon (ZrSiO4) samples were irradiated at 100K with 400 keV Ar+ and Xe+ ion beams to fluences ranging from 5x1013 to 5x1015 ions/cm2. Rutherford backscattering spectroscopy (RBS) experiments were completed to study the dechanneling of He ions in the irradiated zircons. Cross-sections of some irradiated samples were prepared, and the zircon microstructure was examined by highresolution transmission electron microscopy (HRTEM). At doses greater than 8x1014 ions/cm2 or 0.8 dpa (displacements per atom), RBS channeling experiments showed the presence of a disordered or amorphous layer. The electron microscopy confirmed the presence of an amorphous layer extending over a depth of 300 to 350 nm (Ar+ irradiation) and 200 nm (Xe+ irradiation) in agreement with the damage layer depth calculated by TRIM. At depths extending beyond the damage peak, TEM reveals an amorphous layer with “islands” of crystalline material of σ 30 nm in size. These experiments show that RBS and TEM are complementary techniques in investigating radiation effects in irradiations of bulk ceramic.