High resolution X-ray diffraction studies on unirradiated and irradiated strontium hexaferrite crystals

摘要

High-resolution X-ray diffraction technique, employing a three-crystal monochromator-collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li~(3+) ion beams at room temperature with a fluence value of 1 x 1014 ions/cm2. The diffraction curves of the irradiated crystals suggest the possibility of creation of low angle grain boundaries and other point/clusters of defects causing amorphization in the irradiated crystals. The perfection of the irradiated and unirradiated (0001) cleaved surfaces of the crystals is studied using the bulk method of X-ray topography. The topographs supplement the findings suggestive of modifications in the crystalline quality of SrFe_(12)O_(19) on irradiation with SHI of Li~(3+). Etching of the (0001) cleaved surfaces in H_3PO_4 at 120° C suggests that the dissolution characteristics of the surfaces get affected on irradiation with SHI of Li~(3+), besides supporting the findings of HRXRD and X-ray topography regarding modifications in the perfection of SrFe_(12)O_(19) on irradiation.