The effect of zirconium implantation on the structure of sapphire

Sina, Younes; McHargue, C.J.; Duscher, Gerd; Zhang, Yanwen

doi:10.1016/j.nimb.2011.12.026

Cited by 4 publications

(3 citation statements)

References 25 publications

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“…In previous studies, TEM results confirmed the presence of the amorphous phase at fluences greater than 2 × 10 16 ions cm -2 [9,20]. The spectra contained in Figure 1 establish the amorphization fluence to lie in the interval 0.75-1.5 × 10 16 cm -2 .…”

Section: Methodssupporting

confidence: 73%

The defect structure of sapphire produced by implantation of Zr and Zr plus O: threshold fluence for amorphization and optical properties

Sina

Townsend

McHargue

et al. 2012

Phys. Status Solidi C

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Zirconium implantation‐induced amorphization has been investigated with Rutherford back scattering spectrometry along a channeling direction (RBS‐C) using 2 MeV He+. Ion implantation was carried out at the energy of 175 keV, with fluences of 2×1015 to 2×1016 Zr+/cm2 at room temperatures. The critical amorphization fluence at room temperature was determined as ∼1.5×1016 Zr+/cm2 corresponding to ∼ 40 dpa; ∼2.7% peak Zr‐concentration) which is a lower damage energy than that reported for implantation with ions of similar mass and energy. The effect of post implantation of oxygen into a pre‐implanted sample (with zirconium) was investigated. The RBS results show that oxygen implantation in a crystalline sample increases the damage only slightly and slightly broadens the Zr profile. For the fluences above thresh‐old for amorphization, post implantation by oxygen has very little effect on the residual damage or on the Zr distribution. The presence of both F and F+ centers were indicated by optical absorption (OA) measurements. The OA spectra show the concentration of F and F+ centers increases with increasing fluence with some changes resulting from oxygen implantation of a pre‐zirconium‐implanted sapphire. This alters the relative concentrations of F and F+ centers. The F‐type center concentrations for the samples were calculated using Smakula's equation. Photoluminescence (PL) at an excitation of 255 nm confirms the presence of both F and F+ centers with emission peaks at about 420 and 325 nm respectively. The PL spectra suggest that oxygen implantation decrease the concentration of the both species, consistent with the OA results (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Methodssupporting

confidence: 73%

The defect structure of sapphire produced by implantation of Zr and Zr plus O: threshold fluence for amorphization and optical properties

Sina

Townsend

McHargue

et al. 2012

Phys. Status Solidi C

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“…As obtained by cross-sectional nano-indents ( Figure 5(c)), experimental damage profiles were 50-100 nm: 2-4 times of the SRIM estimate. This study also used MD simulations: stated [67,68,[77][78][79][80][81][82][83][84][85][86][87][88][89] to capture the ballistic stage of radiation damage. Largescale MD simulations have challenges, mainly in terms of capturing relevant time and length scales.…”

Section: Discussionmentioning

confidence: 99%

“…Simulations involved standard SRIM [70][71][72] profile and more detailed MD [67,68,[79][80][81][82][83][84][85][86][87][88][89]. For MD, two simulation boxes, of appropriately orientated pure Zr single crystals, were created.…”

Section: Simulations Detailsmentioning

confidence: 99%

Orientation sensitivity of focused ion beam damage in pure zirconium: direct experimental observations and molecular dynamics simulations

Revelly

Srinivasan

Panwar

et al. 2014

Philosophical Magazine

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A high-purity predominantly single crystalline zirconium was subjected to controlled focused ion beam (FIB) damage. Damage estimates were obtained from electron backscattered diffraction (EBSD) and nano-indentation measurements on exactly the same area/orientation. The damage kinetics, between different crystallographic orientations, differed by one order of magnitude and a clear hierarchy of orientation sensitive ion damage emerged. Use of a simple geometric approach, linear density of atoms and corresponding scattering cross-sections to impinging gallium ions, could differentiate between extreme damage kinetics; but failed when such differences were relatively minor. Numerically intensive molecular dynamics (MD) simulations, on the other hand, were more effective. However, MD simulations or direct EBSD observations failed to justify anisotropic irradiation hardening (AIH): 3-8 times more hardening for near basal. Though explanation for AIH is indirect, evidence and rationalization for orientation-sensitive radiation damage appears clear and statistically reproducible.

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