Radioluminescence of alumina during proton and heavy ion irradiation

Photoluminescence study of swift heavy ion (SHI) induced defect centers in sapphire

“…Therefore, the continuos increase in intensity of F 2þ 2 defect center (546 nm) in our samples at initial fluence can be assigned to the increased concentrations of F + defect centers (oxygen vacancies) as a result of Ni ion irradiation [11]. The decrease in the intensity of this defect center at higher fluence can be attributed to annihilation of F + defect centers resulting from a higher disorder induced by irradiation or due to the irradiation induced clustering (growing the sizes of defects) of defect centers [6,17]. Diffusion of defect centers (F + ), as a result of enhanced production, in the lattice could also be the probable reason for this reduction [6].…”

“…Above fluence 1 · 10 16 ion/m 2 the intensity is found to decrease. This decrease in intensity may be associated with the clustering or diffusion of defect centers or their conversion into F + or F 2þ 2 defect centers at higher fluence [6,17].…”

“…The decrease in the intensity of this defect center at higher fluence can be attributed to annihilation of F + defect centers resulting from a higher disorder induced by irradiation or due to the irradiation induced clustering (growing the sizes of defects) of defect centers [6,17]. Diffusion of defect centers (F + ), as a result of enhanced production, in the lattice could also be the probable reason for this reduction [6]. The initial luminescence could be due to the pre-existing defect centers present in the sample [7].…”

“…These centers are associated with luminescence bands centered at 415, 330, 518, 385 and 550 nm, respectively [4]. Understanding of radiation induced processes (light emission and defect production) is the important issue for prospective use of optical and insulating materials based on Al 2 O 3 , for example, in the diagnostic systems of fusion reactors [6]. Although, a number of such studies using low energy heavy ions irradiation in sapphire [7][8][9] have been made, there is a lack of sufficient and systematic work to correlate the defects center formation due to swift heavy ions.…”

Amorphization of sapphire induced by swift heavy ions: A two step process

“…Because of the excellent physicochemical properties for many industrial applications (hardness, chemical insensitivity, refractory behaviour, transparency over a wide wavelength range) of Al 2 O 3 , many investigations have been performed modifying the microstructural [1][2][3][4][5][6][7], surface state [8][9][10] and optical properties [11][12][13][14][15][16] induced in aAl 2 O 3 by ion irradiation in the electronic energy loss regime. These modifications result from complex interactions involving the slowing down process of the incident ions that induces defect creation and structural transformations in the host matrix [17].…”