Showing papers on "Fluence published in 2003"
TL;DR: Observations of the structural evolution of aluminum as it underwent an ultrafast laser–induced solid-liquid phase transition provide an atomic-level description of the melting process, which is best understood as a thermal phase transition under strongly driven conditions.
Abstract: We used 600-femtosecond electron pulses to study the structural evolution of aluminum as it underwent an ultrafast laser–induced solid-liquid phase transition. Real-time observations showed the loss of long-range order that was present in the crystalline phase and the emergence of the liquid structure where only short-range atomic correlations were present; this transition occurred in 3.5picoseconds for thin-film aluminum with an excitation fluence of 70 millijoules per square centimeter. The sensitivity and time resolution were sufficient to capture the time-dependent pair correlation function as the system evolved from the solid to the liquid state. These observations provide an atomic-level description of the melting process, in which the dynamics are best understood as a thermal phase transition under strongly driven conditions.
853 citations
TL;DR: In this paper, the authors studied the ablation of solids under femtosecond laser pulses using a two-dimensional molecular-dynamics model and showed that different expansion regimes develop as a function of the injected energy.
Abstract: The ablation of solids under femtosecond laser pulses is studied using a two-dimensional molecular-dynamics model. The simulations show that different expansion regimes develop as a function of the injected energy. The origin of these regimes lies in changes of the thermodynamical relaxation path the material follows when the intensity of the laser increases. The shape of the pressure waves generated as a result of the absorption of the pulse is shown to vary from bipolar at low fluence to unipolar at high fluence, as a result of the decrease of the tensile strength of the material with temperature. By combining these results with an analysis of the thermodynamical trajectories for different portions of the target, we show that four different mechanisms can account for ablation at fluences below the threshold for plasma formation, namely spallation, phase explosion, fragmentation, and vaporization. These mechanisms are characterized in detail; it is demonstrated that they can occur simultaneously in different parts of the target.
292 citations
TL;DR: In this paper, the authors present experimental results on hydrogen blister formation on powder metallurgy tungsten (PM-W) surface under low energy (1021 m−2 ǫs−1) hydrogen plasma irradiation in a divertor plasma simulator-NAGDIS-I.
108 citations
TL;DR: In this article, it was shown that linear arrays of silicon nanoparticles with fairly uniform size that extended up to a millimeter were formed if the irradiation was performed using polarized light and non-polarized laser light with the same fluence was used to illuminate an initially flat surface.
Abstract: Irradiation with polarized laser light of 248-nm wavelength induces the formation of periodic undulations ∼10-nm-highon flat silicon substrates. The wavelength of these periodic structures is a function of the light wavelength and the angle of incidence of the laser beam. Linear arrays of silicon nanoparticles with fairly uniform size that extended up to a millimeter were formed if the irradiation was performed using polarized light. When non-polarized laser light with the same fluence was used to illuminate an initially flat surface, non-aligned nanoparticle strings were obtained. However, if part of the irradiated area was microstructured, nanoparticle linear arrays resulted in the vicinity of the microstructured region. An analysis on the evolution of these nanostructures is presented. Nanocolumns could be grown on top of every cone of a microstructured surface upon cumulative laser irradiation with non-polarized light, reaching a height of ∼3 μm and a diameter of 100–200 nm. The mechanisms of nanocolumn origin and growth are analyzed.
107 citations
TL;DR: In this paper, the ablation of ionized silicon is studied using near-infrared femtosecond laser pulses in the fluence regime from 1 to 9 J/cm2.
Abstract: The ablation of ionized silicon is studied using near-infrared femtosecond laser pulses in the fluence regime from 1 to 9 J/cm2. Two major peaks are observed in the mass spectrum corresponding to Si+ and Si2+. In the time-of-flight transients of Si+, a bimodal structure is observed. The fast Si+ peak corresponds to a velocity half of that observed for Si2+. This momentum scaling is clearly indicative of a Coulomb explosion.
94 citations
TL;DR: In this article, high-electron mobility transistors and corresponding unprocessed material were characterized as a function of 1.8 MeV proton fluence and showed degradation of the electrical contacts at low fluences and degradation of channel properties for higher fluences.
Abstract: We have characterized high-electron mobility transistors and corresponding unprocessed material as a function of 1.8 MeV proton fluence. Electrical data shows degradation of the electrical contacts at low fluences (10/sup 11/-10/sup 14/ p/sup +//cm/sup 2/) and degradation of the channel properties for higher fluences. In conjunction with the electrical data, cathodoluminescence and secondary-ion mass spectrometry results suggest mechanisms for the higher fluence degradation.
83 citations
TL;DR: In this paper, the position and intensity of the spectral hole in the absorption band of poly[2-methoxy-5-(3′,7′-dimethyl octyloxy)-1-4-phenylene vinylene] (MDMO-PPV): methanofullerene (PCBM) composite films were monitored as a function of time in the 10 ns-10 μs time range.
Abstract: Transient, nonresonant, hole-burning spectroscopy has been used to study the charge recombination process in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1-4-phenylene vinylene] (MDMO-PPV): methanofullerene (PCBM) composite films. The position and intensity of the spectral hole in the absorption band of MDMO-PPV have been monitored as a function of time in the 10 ns–10 μs time range. A time-dependent redshift is observed. The intensity of the spectral hole decays with time according to a power law (∝t−α). The exponent α≈0.5 is found to be nearly independent of the excitation fluence in the range 0.05–2 mJ/cm2. The depth of the spectral hole depends sublinearly on the excitation fluence (I) and can be described by (∝Γ−β) with β∼0.5. The time-dependent redshift and the power-law type time decay can be reproduced by numerical simulations. The Monte Carlo method is used to simulate the hopping dynamics of the photoinduced charges in a lattice of energetically disordered sites before they eventually recombine at ...
72 citations
TL;DR: In this article, the electron energy threshold, fluence, and temperature dependence for O2 production during low-energy (5 −100 eV) electron bombardment of thin amorphous and crystalline D2O ice films deposited on a Pt(1 −1 1) substrate in vacuum.
71 citations
TL;DR: In this paper, a Ti:sapphire femtosecond laser (780 nm, 110 fs) was used to process polytetrafluorethylene (PTFE) in ambient air.
Abstract: Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat resistant) The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition In this paper, laser processing of PTFE in ambient air by a Ti:sapphire femtosecond laser (780 nm, 110 fs) is investigated It is found that the pulse number on each irradiated surface area must be large enough for a clear edge definition and the ablated depth increases with the pulse number The air ionization effect at high laser fluences not only degrades the ablated structures quality but also reduces the ablation efficiency High quality microstructures are demonstrated with controlling laser fluence below a critical fluence to exclude the air ionization effect The ablated microstructures show strong a
65 citations
TL;DR: In this article, a femtosecond pulsed Ti:sapphire laser (pulse width=120 fs, wavelength=800 nm, repetition rate=1 kHz) was employed to perform laser ablation of 1-μm-thick silicon carbide (3CSiC) films grown on silicon substrates.
Abstract: A femtosecond pulsed Ti:sapphire laser (pulse width=120 fs, wavelength=800 nm, repetition rate=1 kHz) was employed to perform laser ablation of 1-μm-thick silicon carbide (3CSiC) films grown on silicon substrates. The threshold fluence and ablation rate, useful for the micromachining of the 3CSiC films, were experimentally determined. The material removal mechanisms vary depending on the applied energy fluence. At high laser fluence, a thermally dominated process such as melting, boiling and vaporizing of single-crystal SiC occurs. At low laser fluence, the ablation is a defect-activation process via incubation, defect accumulation, formation of nanoparticles and final vaporization of boundaries. The defect-activation process reduces the ablation threshold fluence and enhances lateral and vertical precision as compared to the thermally dominated mechanism. Helium, as an assistant gas, plays a major role in improving the processing quality and ablation rate of SiC thin films due to its inertness and high first ionization energy.
63 citations
TL;DR: In this article, nonlinear optical absorption in silver nanosol was investigated at selected wavelengths (456 nm, 477 nm and 532 nm) using open aperture Z-scan technique.
Abstract: Nonlinear optical absorption in silver nanosol was investigated at selected wavelengths (456 nm, 477 nm and 532 nm) using open aperture Z-scan technique. It was observed that nature of nonlinear absorption is sensitively dependent on input fluence as well as on excitation wavelength. Besides, the present sample was found to exhibit reverse saturable absorption (RSA) and saturable absorption (SA) at these wavelengths depending on excitation fluence. RSA is attributed to enhanced absorption resulting from photochemical changes. SA observed for fluence values lower and higher than those corresponding to RSA are, respectively, attributed to plasmon bleach and saturation of RSA.
TL;DR: In this paper, a three-layer structure for the irradiated anatase powders was studied by Raman microprobe spectroscopy and atomic force microscopy (AFM).
TL;DR: In this paper, an analytical model of the multi-pulse ablation process was derived, and the matching conditions for the level and distribution of laser intensity, parameters of the optical focusing scheme and material parameters were derived in an explicit analytical form.
Abstract: Systematic experimental studies of KrF laser microdrilling in polymers (PMMA, PET, PS, PC, PI, PEEK) have led to high-aspect-ratio microholes (up to 600) in a final stationary profile. From these results, an original theory is derived, which gives an analytical modeling of the multi-pulse ablation process. In the experiments holes with diameters in the range of 10 to 100 μm and from one to several tens of millimeters in depth, depending on fluence, are obtained for various polymers. The stationary depth increases with fluence and this dependence is well reproduced by the present model. The particular mechanism of radiation propagation and absorption inside the deep laser keyhole is clarified, and does not suggest a significant channeling of the radiation in the forming hole. This mechanism alongside the angular divergence of the beam are important key factors for the mathematical description of high-aspect-ratio laser drilling. As a result (a) the controlling factors of drilling are outlined; (b) final keyhole profile and depth vs. incident fluence are calculated for the rectangular, Gaussian and other spatial distributions of the beam and the comparison with the experiment is given; and (c) the laser drilling is optimized, i.e. the matching conditions for the level and distribution of laser intensity, parameters of the optical focusing scheme and material parameters are derived in an explicit analytical form, allowing us to produce deep keyholes with practically parallel side walls and aspect ratios as high as 300–600.
TL;DR: Evidence of a decoupling between ablation and ionization is found in irradiation effects at low and high laser fluence on 2,5-dihydroxybenzoic acid large crystals.
TL;DR: In this article, the optimal focussing for ablation has been investigated and first results towards the structuring of a ridge waveguide are presented, which is most promising for waveguide patterning of DAST surfaces for integrated optics applications.
01 May 2003-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, the effects of 50 MeV Li3+ ion beams in polyethylene terephthalate (PET) films were studied with respect to their structural and electrical properties by using Fourier transform infrared (FTIR) spectroscopy and ac electrical measurement in the frequency range: 50-100 kHz at different temperatures of 30-150 °C.
Abstract: Irradiation effects of 50 MeV Li3+ ion beams in polyethylene terephthalate (PET) films were studied with respect to their structural and electrical properties by using Fourier transform infrared (FTIR) spectroscopy and ac electrical measurement in the frequency range: 50–100 kHz at different temperatures of 30–150 °C. It is found that ac resistivity of PET decreases as frequency increases. The temperature dependencies of dielectric loss tangent exhibit a peak (Tg) at 60 °C. The capacitance value of irradiated PET is almost temperature independent and ones increases with an increasing of lithium fluence. FTIR spectra show various bands related to C–H, CO, C–O–C molecular bonds and groups which get modified or break down due to ion beam irradiation.
TL;DR: In this paper, a continuous wave CO2 laser annealing technique at a relatively low temperature was studied on a Pt/Ti/SiO2/Si substrate for fabricating well-crystallized sol-gel derived (La05Sr05)MnO3 (LSMO) buffer electrode layers and ferroelectric Pb(Zr052Ti048)O3(PZT) thin films using a continuous-wave CO2-laser-annealing approach.
Abstract: Fabrication of well-crystallized sol-gel derived (La05Sr05)MnO3 (LSMO) buffer electrode layers and ferroelectric Pb(Zr052Ti048)O3 (PZT) thin films using a continuous wave CO2 laser annealing technique at a relatively low temperature was studied on a Pt/Ti/SiO2/Si substrate Resistivity, carrier concentration and Hall mobility of laser-annealed conducting oxide LSMO films were optimized by changing the radiation fluence and the substrate temperature The minimum resistivity of 127×10−4 Ω cm was obtained for LSMO/Pt(Si) films prepared by laser irradiating at a fluence of 533 W/cm2 with a simultaneous substrate heating at a temperature of 300 °C The laser-annealed PZT films coated on LSMO/Pt(Si) substrate shows enhancement in remanent polarization from 101 to 173 μC/cm2 as the PZT irradiated with a laser fluence of 433–483 W/cm2 The PZT(483 W/cm2)/LSMO(533 W/cm2)/Pt(Si) films showed a good fatigue resistance after 1×1010 switching cycles with a bipolar electric field of 300 kV/cm, implying the feasibility of fabricating reliable ferroelectric-oxide electrode heterostructures using CO2 laser annealing at temperatures lower than 400 °C
28 May 2003
TL;DR: In this article, the growth of damage sites on the rear surface of fused silica plates was studied as a function of fluence and angle of incidence, and it was determined that the relevant fluence for growth was that taken inside the material.
Abstract: The growth of damage sites on the rear surface of fused silica plates was studied as a function of fluence and angle of incidence. At 1053 nm, a 70 J beam, 3 ns in pulselength, was directed to a 5 cm 2 zone on a bare fused silica window. Initiation and growth was observed. The growth of previously initiated sites was also studied. Growth is exponential in nature. The experiments allow for the determination of the growth coefficient as a function of fluence. At 355 nm, damage sites were irradiated at various angles of incidence, with a tripled Nd:Yag laser, spatially Gaussian, 2.5 ns in pulselength. By fitting growth with an exponential law, it was determined that the relevant fluence for growth was that taken inside the material.
TL;DR: In this article, surface modification and helium retention on powder metallurgy tungsten and plasma sprayed Tungsten coated CFC exposed by low energy (100 eV) high flux (383×10 21 −120×10 22 m −2 ǫs −1 ) helium plasma have been investigated.
TL;DR: In this paper, the effect of ion implantation including ion species (N-2(+) and C3H8+) and the fluences (1x10(14)-5x10 (15) ions/cm(2)) on the surface energy of ultrahigh molecular weight polyethylene (UHMWPE) was investigated.
Abstract: The effect of ion implantation including ion species (N-2(+) and C3H8+) and the fluences (1x10(14)-5x10(15) ions/cm(2)) on the surface energy of ultrahigh molecular weight polyethylene (UHMWPE) were investigated. The total surface energy increases significantly after implanting with the fluence of 1x10(14) ions/cm(2) regardless of ion species, then, the total surface energy slightly increases for N-2(+) implanted UHMWPE and decreases slightly for C3H8+ implanted UHMWPE with a further increase of fluence. The structural changes of UHMWPE with different fluence for different ion species are very similar. The linear chains of UHMWPE are damaged and cross linking is generated after implantation. As the fluence increases, the polymer surface becomes more disordered, and the surface becomes hydrogenated amorphous carbon when the fluence exceeds 1x10(15) ions/cm(2). The surface roughness increases with the increase of the fluence regardless of ion implantation species. (C) 2003 American Institute of Physics.
TL;DR: In this article, the authors used Ti:sapphire laser pulses with durations from 30 to 340 fs (centre wavelength 800nm, repetition rate 1.8 kHz) for ablation experiments in air.
TL;DR: By postdeposition nanosecond laser irradiation at 532 nm with a relatively low laser fluence of typically ∼50 mJ/cm2, Ag- and Au-island films sputter-deposited on mica could be converted to a dense...
Abstract: By postdeposition nanosecond laser irradiation at 532 nm with a relatively low laser fluence of typically ∼50 mJ/cm2, Ag- and Au-island films sputter-deposited on mica could be converted to a dense...
TL;DR: In this paper, the excitation fluence and magnetic field dependence of terahertz (THz) radiation power from InAs was investigated, and the results were explained by considering different THz-radiation mechanisms from the InAs surface with or without photoexcited carrier screening.
Abstract: The excitation fluence and magnetic field dependence of terahertz (THz) radiation power from InAs is investigated. At low excitation fluence, an enhancement of the THz-radiation power is observed independent of the magnetic-field direction. As the excitation fluence is increased, a crossover of the terahertz radiation mechanism is observed. At excitation fluence above this crossover, the radiation power is either enhanced or reduced depending on the magnetic-field direction. These results are explained by considering the different THz-radiation mechanisms from the InAs surface with or without photoexcited carrier screening.
TL;DR: In this paper, the authors investigated the defects created in optical grade fused silica due to 200 MeV silver ion irradiation, and the fluence dependent optical and paramagnetic behaviours of these defects were studied using UV-visible absorption spectroscopy, photoluminescence spectroscopic, infrared (IR) absorption and electron paramagnetic resonance.
Abstract: Investigation of defects created in optical grade fused silica due to 200 MeV silver ion irradiation is reported. Paramagnetically positively charged oxygen vacancies or neutral dangling Si bonds (E' centres), non-bridging oxygen hole centres (NBOHC) and non-paramagnetic defects like B2 bands are observed. The fluence dependent optical and paramagnetic behaviours of these defects are studied using UV–visible absorption spectroscopy, photoluminescence spectroscopy, infrared (IR) absorption and electron paramagnetic resonance. It is observed that generation of E' centres, NBOHC and B2 bands gets saturated beyond a fluence of 1 × 1012 ions cm−2. IR spectra showing saturation in transmission at this fluence also support this observation. At this fluence samples get fully covered with latent tracks containing these defects.
TL;DR: In this article, the authors report on recent irradiation experiments on magnetic tunnel junctions (MTJ) using either light (C, O) or heavy (Ni) ion beams with energies in the range of 10 MeV/A.
Abstract: In this article, we report on recent irradiation experiments on magnetic tunnel junctions (MTJ) using either light (C, O) or heavy (Ni) ion beams with energies in the range of 10 MeV/A. For all ions, albeit with different fluence thresholds, the tunnel magnetoresistance decreases irreversibly with increasing ion fluence, with conversely little or no impact on overall resistance. This can only be explained by a modification of the alumina barrier stoechiometry, rather than by interdiffusion. Measurements on irradiated so-called “spin-mirrors” sheet films show that AlOx/metal interface is altered by radiations. Finally, it is shown that MTJs are not a fortiori insensible to swift heavy ion bombardment.
19 Feb 2003
TL;DR: In this paper, three different ablation thresholds were distinguished in all metals and the lowest ablation threshold was of one order of magnitude lower than the one observed previously, in the range of 0.018-0.18 J/cm2.
Abstract: Laser ablation of Cu, Al, Fe, Zn, Ni, Pb, and Mo by short pulse laser (800nm wavelength, 70fs pulse duration, 0.01-28 J/cm2 fluence range) in air was studied. Three different ablation thresholds were distinguished in all metals. The lowest ablation threshold was of one order of magnitude lower than the one observed previously. In the fluence range of 0.018-0.18 J/cm2 the ablation rate was ≈0.01 nm/pulse. A dependence of the threshold on the pulse duration was demonstrated in the range of 70 fs- 5 ps for cupper. As the laser pulse duration increased, the ablation threshold had the tendency to be higher. A periodic structure was observed at the bottom of the crater in all metals. The spacing d of the patterned structure was determined to be d=300±40 nm for 0.07 J/cm2 and d=600±40 nm for 0.22 J/cm2. The spacing depended on the laser fluence rather than on laser wavelength.
TL;DR: In this article, the influence of the ion-charge state on the mixing process was studied in Fe/Si by 100-keV Ar8+-ion implantation, in addition to corresponding irradiations with singly charged ions at the same energy.
Abstract: Silicide formation and ion beam mixing of Fe/Si bilayers due to Ar-, Xe- and Au-ion irradiations at room and liquid-nitrogen temperatures were investigated. For the study of silicide phase formation, the Fe/Si bilayers were irradiated with 100-keV Ar+, 250-keV Xe+, 700-keV Xe2+ or 400-keV Au+ ions at fluences of 1×1015 to 2×1016 ions/cm2. The influence of the ion-charge state on the mixing process was studied in Fe/Si by 100-keV Ar8+-ion implantation, in addition to the corresponding irradiations with singly charged ions at the same energy. Changes in the samples were analyzed by Rutherford backscattering spectroscopy, conversion electron Mossbauer spectroscopy, X-ray diffraction and atomic force microscopy. Pronounced structural changes and the intermixing of the components at the Fe/Si interfaces were measured as a function of the ion species, ion fluence and sample temperature. A linear correlation between the interface broadening and the fluence was observed for all the cases. Mossbauer analysis with enriched 57Fe layers revealed the onset of phase formation out of the solid solution. In order to interpret the mixing rates in this most general case, we considered mixing through thermal local or global spikes and compound formation. The highly charged Ar8+-ion irradiation produced a higher athermal mixing rate compared to singly charged Ar+ ions, and this result could not be explained by the above models.
TL;DR: In this article, the effects of lattice damage level, pump fluence, and temperature on carrier dynamics in thin silicon films were investigated, and the authors derived the carrier relaxation time and effective carrier mobility for the three samples.
Abstract: We study the effects of lattice damage level, pump fluence, and temperature on carrier dynamics in thin silicon films. Two samples of radiation-damaged silicon-on-sapphire (RD-SOS) and one amorphous silicon thin film on sapphire were investigated. The first RD-SOS sample was O+ implanted with doses of 1×1013 cm−2 at 100 and 200 keV; the second RD-SOS sample was O+ implanted with a dose of 1×1015 cm−2 at 100 and a second dose of 2×1015 cm−2 at 200 keV; the third sample was a nonhydrogenated amorphous-silicon thin film grown by electron-beam evaporation. Carrier concentrations up to 7.4×1020 cm−3 were injected into the samples with 100 fs, 400 nm pump pulses, while the transient optical properties were probed with subpicosecond-wide terahertz (THz) pulses. Using a thin film Drude model, we derived the carrier relaxation time and effective carrier mobility for the three samples. The increase of lattice damage decreased both the relaxation time constant and the carrier mobility. A slight increase in relaxation time was observed for increasing pump fluence, but mobility values were not affected. No change in relaxation time or mobility was found for temperatures from 5 to 300 K. We find average relaxation time constants of 5.5 ps in the first sample, 1.4 ps in the second sample, and 0.58 ps in the third sample, and average carrier mobility values of 383, 44, and 4.4 cm2/V s, respectively. The presence of a single relaxation time constant is consistent with a trap-influenced relaxation mechanism and not of Auger recombination for carrier concentrations <1021 cm−3, indicative of the absence of thermally activated processes in the relaxation mechanism.
TL;DR: In this paper, the modified two-dimensional hydrodynamic code POLLUX has been used to simulate the ablation of magnesium, copper, and lead targets in the early stage of expansion by 30 ns, 0.248 μm KrF excimer and 1.064 μm Nd-YAG lasers at fluences of 3-10
Abstract: The modified two-dimensional hydrodynamic code POLLUX has been used to simulate the ablation of magnesium, copper, and lead targets in the early stage of expansion (<100 ns) by 30 ns, 0.248 μm KrF excimer and 1.064 μm Nd–YAG lasers at fluences of 3–10 J/cm2. The results of magnesium ablation using KrF laser with different fluences are compared and found to be in reasonably good agreement with the experimental results. A comparative study of laser ablation for magnesium, copper, and lead has been made by simulation using Nd–YAG lasers at fluence 10 J/cm2. The temporal evolution of surface temperature of the target, ablated vapor mass, and ionization fraction of plasma plume is studied for each material. The simulated temporal evolution and spatial distribution of electron density, electron temperature, and axial velocity of ablated plume of each material are studied and the results are compared. It is found that the plume expansion follows adiabatic behavior and is slowed down with increasing atomic mass. ...
01 May 2003-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, the disordering in the fused lithium metatitanate (Li 2 TiO 3 ) irradiated with high energy ions (160 MeV Xe, 80 MeV O) was examined by room-temperature X-ray diffraction and Raman spectroscopy.
Abstract: The disordering in the fused lithium metatitanate (Li 2 TiO 3 ) irradiated with high energy ions (160 MeV Xe, 80 MeV O) was examined by room-temperature X-ray diffraction and Raman spectroscopy. The exposure of Li 2 TiO 3 to Xe ions at fluences of 3.3 × 10 16 and 3.4 × 10 18 /m 2 was found to cause complete disordering in its surface layer, unlike the surface layer exposed to O ions up to maximum fluence of 1.4 × 10 20 /m 2 . An extent of disordering with irradiation is associated with the electronic stopping power of the incident ions in Li 2 TiO 3 rather than the fluence and accumulated radiation dose.