Swift heavy ion induced structural, iono and photoluminescence properties of β-CaSiO _3:Dy ~(3+) nanophosphor

摘要

CaSiO _3:Dy ~(3+) (1-5 mol%) nanophosphors have been prepared by a low temperature solution combustion method. The structural and luminescence (ionoluminescence; IL and photoluminescence; PL) studies have been carried out for pristine and ion irradiated samples. The XRD patterns of pristine sample show a prominent peak at (3 2 0) for the monoclinic structure of β-CaSiO _3. Upon ion irradiation, the intensity of the prominent peak is decreased at the fluence of 7.81 × 10 ~(12) ions cm ~(-2) and at higher fluence of 15.62 × 10 ~(12) ions cm ~(-2), the prominent peak completely vanishes. The decrease in peak intensity might be due to the stress induced point defects. On-line IL and in situ PL studies have been carried out on pelletized samples bombarded with 100 MeV Si ~(7+) ions with fluences in the range (7.81-15.62) × 10 ~(12) ions cm ~(-2). The characteristic emission peaks at 481,574, 664 and 754 nm recorded in both IL and PL are attributed to the luminescence centers activated by Dy ~(3+) ions. It is found that IL and PL emissions intensity decreases with increase in Si ~(7+) ion fluence. The decrease in intensity can be due to the destruction of Si-O-Si and O-Si-O type species present on the surface of the sample. FTIR studies also confirm the Si-O-Si and O-Si-O type species observed to be sensitive for swift heavy ion (SHI) irradiated samples.