Structural, iono and thermoluminescence properties of heavy ion (100 MeV Si7+) bombarded Zn2SiO4:Sm3+ nanophosphor

Abstract

Structural, iono (IL) and thermoluminescence (TL) studies of Zn2SiO4:Sm3+ (1–5mol%) nanophosphor bombarded with swift heavy ions in the fluence range 3.91×1012–21.48×1012cm−2 have been carried out. The average crystallite sizes for pristine and ion irradiated for 3.91×1012ionscm−2 and 21.48×1012ionscm−2 were found to be 34, 26 and 20nm. With increase of ion fluence, the intensity of XRD peaks decreases and FWHM increases. The peak broadening indicates the stress induced point/clusters defects produced due to heavy ion irradiation. IL studies were carried out for different Sm3+ concentrations in Zn2SiO4 by irradiating with ion fluence of 15.62×1012ionscm−2. The characteristic emission peaks at ∼562, 599, 646 and 701nm were recorded by exciting Si7+ ions in the fluence range 3.91×1012–21.48×1012ionscm−2. These peaks were attributed to 4G5/2→6H5/2 (562nm), 4G5/2→6H7/2 (599nm), 4G5/2→6H9/2 (646nm), and 4G5/2→6H5/2 (701nm) transitions of Sm3+ . The highest emission was recorded at 3mol% of Sm3+ doped Zn2SiO4. TL studies were carried out for 3mol% Sm3+ concentration in the fluence range 3.91×1012–21.48×1012ionscm−2. Two TL glow peaks at 152 and 223°C were recorded. The kinetic parameters (E, b, and s), were estimated using Chen's peak shape method. Simple glow curve structure (223°C), highly resistive, increase in TL intensity up to 19.53×1012ionscm−2, simple trap distribution makes Zn2SiO4:Sm3+ (3mol%) phosphor highly useful in radiation dosimetry.