Ion Beam Induced Luminescence Spectra Research Articles

Ion beam induced luminescence analysis of europium complexes in styrene-divinylbenzene copolymer-coated spherical silica by proton and argon ion beams irradiation

Ion beam induced luminescence (IBIL) analysis of adsorbents containing Eu complexes was carried out using a 3-MV single-ended accelerator and an azimuthally varying field cyclotron to evaluate structures of complexes in an extraction chromatography. Some adsorbents were prepared by impregnating a styrene-divinylbenzene copolymer-coated porous silica particle (SiO2-P) with extractants. The IBIL spectra of Eu complexes in the adsorbents produced some differences depending on the kinds of extractants. The experimental results imply that the difference in the IBIL spectra of Eu complexes in the adsorbents is caused by the difference in the structures. The only clear luminescence peak in the alkyl diamide amine (ADAAM) with n-octyl and 2-ethylhexyl alkyl chains (ADAAM(Oct, N(EH))) adsorbent was not observed by H+ ion beam irradiation. Meanwhile, the luminescence of Eu could be detected by irradiation of an Ar8+ ion beam. The luminescence of Eu complexes is presumed to be easily detected by high linear energy transfer (LET) beam irradiation. The symmetric properties of Eu complexes were evaluated with the luminescence due to the 5D0 → 7F2 transition, and it is implied that ADAAM with 2-ethylhexyl alkyl chains (ADAAM(EH, N(EH))) is a high asymmetry property. The luminescence intensity of Eu complexes in the adsorbent decreased with the ion beam irradiation because extractants were damaged by the ion beam. This phenomenon was clearly observed by irradiation of high LET ion beam, Ar8+.

Virtual photon approach of cathodoluminescence and ion-beam induced luminescence of solids

A novel analysis of cathodoluminescence (CL) and ion-beam induced luminescence (IBIL) is presented on the basis of virtual photon spectra (VPS) produced by charged particles (electrons or ions) passing by luminescent species such as defects or impurities, in wide band-gap ionic-covalent solids. A discussion is provided for irradiations in a wide range of charged particle kinetic energy by using the Weizsäcker-Williams theory. The computed VPS are found to decay rapidly as a function of virtual photon (VP) energy regardless of particle energy, for close or distant collisions. The electron-energy dependence of experimental CL spectra of sapphire (α-Al2O3) is discussed in relation to the computed VPS for the primary and secondary electrons. The experimental IBIL spectra of α-Al2O3 are also analyzed in this framework for protons and helium ions in the MeV energy range. The variations of stopping power are consistent with the variation of the number of emitted VPs. The decay of IBIL yield versus ion stopping power is discussed on the basis of the variation of the computed VPS, and ionization and excitation induced by primary ions and secondary electrons. This decay is accounted for by a decrease of the yield of low-energy secondary electrons with the subsequent VP emission.

A new optical method for the comparison of the performance of liquid scintillators

This work presents a novel optical method for selecting new liquid compounds for scintillation detectors. This method consists in the evaluation of the optical properties of the compounds and the definition of parameters quantifying their emission yield, based on the study of the scintillation spectra. It is a comparative method as it allows the choice of the best liquid scintillator among many through a step-by-step selection based on: (1) the fluorescence spectra of the matrix, (2) the fluorescence spectra of the matrix with a dye, (3) the Ion Beam Induced Luminescence spectra of the matrix with different dye percentages. We used the proposed method to identify new liquids which may be suitable for neutron detection. This work shows the results of this application: a new organic non-toxic and non-flammable liquid scintillator has been identified.

Temperature dependence of ZnO crystals from ion-beam-induced luminescence

The effect of temperature (300-100 K) on the luminescence behavior of ZnO crystals irradiated with 2 MeV H+ were reported by ion-beam-induced luminescence (IBIL). Compared with constant-temperature IBIL spectra, the fluence mainly affects the luminous intensity, and the peak position shift is mainly affected by the temperature. For deep-band emissions (DBEs) at temperature ranges of 300–200 K, three emission bands exist in the red, orange-red, and green regions. These three emission bands illustrate different temperature dependencies with decreasing temperature: red and orange-red emission bands are not sensitive to temperature and redshift to green emission bands. The origins of three emission bands are the radiative recombination of deeply trapped holes with shallowly trapped electrons at the Oi, transition from the Zni to Oi level and transition related to oxygen vacancy levels. For DBE of 200–100 K, the orange-red emission band is not sensitive to temperature and has the same origin as the high-temperature section. The temperature dependence of UV band emission associated with recombination of excitons is caused by the temperature-induced band-gap shrinkage. The abnormal movement with temperature of violet emission band associated with Zni results from competition between localization effect at Zni and the band-gap shrinkage.

Optical spectral study of Nd3+ in YSZs with ion beam-induced luminescence

Ion beam-induced luminescence (IBIL) spectroscopy based on the stark level characteristics of trivalent neodymium (Nd3+): 4F3/2 → 4I9/2 emissions is a powerful tool for characterizing material molecules and crystal structures and quantifying radiation damage. Its spectral parameters are considered to characterize the molecular and crystal structure environment and to track the degree of short-range order disturbance of cationic sites. However, IBIL-based related technologies have rarely been reported. In this article, the IBIL of Nd3+ in yttria-stabilized zirconia (YSZs) was studied in the near-infrared region, especially the Nd3+: 4F3/2 → 4I9/2 emission at room temperature with 2 MeV H+. The results show that 1) a single IBIL spectrum carries as much information about the structure of a substance as the PL spectrum. 2) The surrounding crystal environments of Nd3+ cations in the three samples are consistent. 3) H+ does little damage to the sample in the course of analysis.

The origin of the 500 nm luminescence band related to oxygen vacancies in ZrO2

In this paper, ion-beam-induced luminescence (IBIL) spectra of raw ZrO2 irradiated with 2 MeV H+ ions and photoluminescence (PL) spectra of annealed (200, 500 and 800 °C in air, nitrogen or oxygen) ZrO2 were investigated. The luminescence intensity decreased with increasing fluence, which indicated that the concentration of luminescence centers decreased during irradiation. The PL spectral results show that, with increasing partial pressure of oxygen during annealing, the intensity of luminescence decreases due to the decrease in oxygen vacancies. First-principles calculations were used to study the formation energy and transition level for oxygen vacancies (Vo), Ti-substituted Zr (Ti) and Ti adjacent to the nearest Vo (Ti-Vo) complex. The binding energies of Ti3+ and Vo + are 2.10 eV, which indicates that oxygen vacancies benefit the formation of Ti3+. The calculated configuration coordinate diagram and IBIL results indicated that Vo is not the luminescence origin. A new light-emitting structure of the Ti-Vo complex (FA center) structure was proposed based on our calculations and previous studies. The calculated results of the luminescence model match the PL and IBIL spectra remarkably. The emission band of ZrO2 at approximately 500 nm was assigned to the FA center or Ti3+ (the eg to t2g transition) adjacent to Vo+.

Synthesis condition effects on the emission enhancement of YBO3 powder

In the present study, self-activated YBO3 powder was successfully synthesized via a facile solid-phase method using ammonium tetraborate tetrahydrate. A modified synthesis temperature (900 °C) reduced the nanoparticle sizes up to 5 nm. Very detailed investigations using different characterization methods such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman and photoluminescence (PL) spectroscopies, and ion beam-induced luminescence (IBIL) were performed. Raman spectrum confirmed the presence of small amounts of boron in BO3 coordination. PL spectroscopy of the synthesized YBO3 powder showed that the prepared sample emitted a strong blue emission band centered at 416 and an intense green emission band centered at 480 nm. Another green emission line at 529 nm with lower intensity was also detected at all excitations. IBIL spectrum showed a broad UV-blue emission line from 220 to 450 nm and two green emission lines. These emission lines were observed without any dopant. They were the result of the size of particles and boron in BO3 coordination which leads to vacancy defects. The results of the study demonstrated that the ultrafine microstructures and the existence of boron in the three-fold coordination played critical roles in receiving new optical properties.

In situ luminescence measurement of 6H-SiC at low temperature**Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11905010), the Fundamental Research Funds for the Central Universities, China (Grant No. 2018NTST04), the China Postdoctoral Science Foundation (Grant No. 2019M650526), and Guangdong Province Key Area R&D Program, China (Grant No. 2019B090909002).

To understand the evolution of defects in SiC during irradiation and the influence of temperature, in situ luminescence measurements of 6H-SiC crystal samples were carried out by ion beam induced luminescence (IBIL) measurement under 2 MeV H+ at 100 K, 150 K, 200 K, 250 K, and 300 K. A wide band (400–1000 nm) was found in the spectra at all temperatures, and the intensity of the IBIL spectra was highest at 150 K among the five temperatures. A small peak from 400 nm to 500 nm was only observed at 100 K, related with the D1 defect as a donor–acceptor pair (D–A) recombination. For further understanding the luminescent centers and their evolution, the orange band (1.79 eV) and the green band (2.14 eV) in the energy spectrum were analyzed by Gaussian decomposition, maybe due to the donor–deep defect/conduction band–deep defect transitions and Ti related bound excition, respectively. Finally, a single exponential fit showed that when the temperature exceeded 150 K, the two luminescence centers’ resistance to radiation was reduced.

Ions beam induced luminescence study of variation of defects in zinc oxide during ion implant and after annealing

<sec>The optical and electrical properties of ZnO related on the type and the concentration of defects in ZnO crystal. Ion implantation and annealing can change the type and the concentration of defects in ZnO. To understand the variation of defects in ZnO during ion implantation and after different temperature annealing, in situ luminescence measurements of ZnO crystal samples were carried out by ion beam induced luminescence (IBIL) during ion implantation of 2 MeV H<sup>+</sup> and then after annealing at 473 K and 800 K in vacuum on the GIC4117 tandem accelerator in Beijing Normal University.</sec><sec>IBIL spectra of ZnO showtwo emission peaks: UV emission, which is called near band emission (NBE), and visible emission, which is called deep band emission (DBE).The high-intensity of DBE and weak NBE of IBIL spectra of ZnOmay be due to the NBE is intrinsic to ZnO samples and therefore is just visibly observed from samples that are virtually defect-free. With the ion implantation, the destruction of the crystal structure and the arising of a mass of defects, inducing the weak intensity NBE and intense DBE.In addition, the overall IBIL spectra of ZnOreveal decrease intensity with the ion fluence,which indicates that the concentration of luminescence centersdecreases duringion implantation.With the H<sup>+</sup> fluence, the concentration of the point defects increases. The point defects migrate and subsequently agglomerate into larger defect clusters. These defect clusters serve as traps for catching electrons and holes, which result in the quenching of luminescence centres. Annealing can help todecompose the defect clusters and repair the defects of crystal. However, amounts of defects and clusters still remain in the irradiated sample annealed at 473 K in vacuum, which acted as nonradiative center and suppress the luminescence induced weak intensity of IBIL. Annealing the sample at 800 K in vacuum may facilitate the decomposition of defect clusters during ion irradiation to point defects and the point defect return to the lattice position that can reduce the nonequilibrium defects inside the crystal and improve the crystallinity of the crystal, which increase the intensity of its IBIL.</sec>

Micro-ion beam-induced luminescence spectroscopy for evaluating SiAlON scintillators

Ion beam-induced luminescence (IBIL) spectroscopy was used for luminescent material characterization and analysis for the investigation of new scintillator families. Under continuous 3 MeV proton microbeam irradiation, the crystal structures of α-SiAlON:Eu, β-SiAlON:Eu, and CaAlSiN3 (CASN) emitted bright luminescence at peak wavelengths of 605, 540, and 670 nm, respectively. As the irradiation progressed, the IBIL intensity of the conventional ZnS:Ag scintillator decreased sharply, whereas that of the SiAlONs and CASN remained within the detection limit. IBIL spectroscopy was performed on individual grains of the SiAlON scintillators. IBIL imaging and spectroscopy of two grains of β-SiAlON:Eu showed that the main peak in the IBIL spectrum of β-SiAlON:Eu obtained from a large-area beam scan consisted of several small peaks, which were observed in spectra from individual grains. Our experimental results suggest that microscopic spectroscopy of IBIL is an effective tool for microscopic material characterization of luminescent targets.

Evaluation of scintillation properties of α- and β-SiAlON phosphors under focused microbeam irradiation using ion-beam-induced luminescence analysis

Two different types of SiAlON phosphors, namely, α-SiAlON:Eu and β-SiAlON:Eu, that have been developed as scintillators are evaluated for their luminescent properties by ion-beam-induced luminescence (IBIL) analysis under 2–3-MeV H+-microbeam irradiation. The IBIL spectra show that both α-SiAlON:Eu and β-SiAlON:Eu have bright luminescence similar to that of ZnS:Ag scintillators. The α-SiAlON:Eu and β-SiAlON:Eu IBIL spectra have peaks at wavelengths of 605 and 540 nm, respectively, which lie in the preferred range of general optical sensors. As the irradiation progresses, the IBIL intensity of conventional ZnS:Ag scintillators decreases sharply, whereas that of the two SiAlONs remains largely unchanged. Moreover, the thermal resistivity of β-SiAlON:Eu is measured by IBIL under temperature control. The IBIL intensity retains half of its original value at the highest temperature of 773 K. The present experimental results reveal the two different types of SiAlON to be potential candidates for a scintillation monitoring tool for harsh environments in which intense beam irradiation at high temperature can be expected.

Development of an ion beam induced luminescence set-up with a temperature controlled target stage and its application

To explore the irradiation damage and the ion beam induced luminescence (IBIL) during ion implantation at various temperatures, a MeV ion beam induced luminescence measuring set-up with a temperature controlled target stage (attainable temperature range from 77 K to 873 k) has been established at the GIC4117 Tandem accelerator in Beijing Normal University. On the IBIL spectra of lithium fluoride (LiF) at various temperatures under the 2 MeV H+ irradiation, the significant influences of temperature on luminescence were observed. Several mechanisms influenced by temperature could be the cause of different evolution behaviors under different temperatures, such as the vacancy migration rate, annealing effect and non-radiative recombination. The ‘‘double-exponential’’ model was employed to get the value of the half-brightness radiation fluence F1/2, to get the information about the sensitivity of photon yield to the irradiation damage and recovery.

Observation of changes in ion beam induced luminescence spectra from organics during focused microbeam irradiation

Continuous measurement of ion beam induced luminescence (IBIL) spectra was demonstrated with organic targets of nicotinamide adenine dinucleotide (NADH), tryptophan, riboflavin, and a polycyclic aromatic hydrocarbon (PAH), which are typically used as markers of biological contaminants in airborne particles. A 3MeV external proton microbeam from a single-ended accelerator at QST/Takasaki was used to probe for changes in the IBIL spectrum using micro-optics sharing a focal point with the microprobe. We find that the decay of IBIL spectra from NADH and riboflavin varied by target organic species. Moreover, new peaks in the IBIL spectrum were recorded by continuous IBIL spectroscopy from the PAH target after destruction of a peak originally obtained in the initial measurement. These results suggest that IBIL monitoring can detect changes in the chemical composition of organics under focused beam irradiation.

Ion beam induced luminescence spectra of lithium fluoride at high-and low-temperature

A new ion beam induced luminescence (IBIL) measuring setup, equipped with a custom-made heating/cooling sample stage (the attainable temperature ranges from 80 K to 900 K), has been established on the GIC4117 tandem accelerator in Beijing Normal University. As the yield of back scattering ions is proportional to the beam flux, an Au-Si surface barrier detector is employed to count the back scattering ions synchronously with collecting the IBIL spectra under the multi-channel scaler (MCS) mode of the multichannel analyzer, making it possible to online monitor the beam current. Then, the yield of back scattering ions is used to correct the intensity of the IBIL spectrum and calculate the ion fluence, for eliminating the influence of the beam current fluctuation. IBIL spectra of pure lithium fluoride (LiF) at different temperatures (100, 200, 290, 450, 550 K) under the 2 MeV H+ irradiation are acquired and the significant influence of temperature on luminescence centers is observed. The emission bands relating to exciton recombination (296 and 340 nm) and impurities (400 nm) are more prominent at low temperatures and present quite lower intensities at high temperatures. Moreover, these luminescent intensities decay with ion fluence increase obviously at high temperatures after initially increasing in the early period of irradiation. The initial increase of the disturbed exciton peak at 296 nm can be attributed to the strained bonds produced by nuclear elastic scattering at a low fluence, which was not observed in previous IBIL measurements under high ionization energy density or high ion beam flux. This observed increase indicates that the emission feature may also originate from the emitting centers relating to point defects, not just from exciton transition near lattice or impurities. The luminescent intensities of F2 color centers (peaked at 670 nm) are dominant at all temperatures, while the luminescent intensities of F3+ color centers (peaked at 540 nm) are not obvious at low temperatures and the luminescent intensities of F3-/F2+ color centers (peaked at 880 nm) are weak at high temperatures. The luminescent intensities of these F-type centers reach saturated values at lower fluences at high temperatures. The different evolution behaviors under different temperatures can be due to the influence of temperature on the vacancy migration rate and the non-radiative recombination. In addition, the surface charge accumulation may lead to the luminescent intensities of color centers reaching saturated values at higher fluences, compared with the previous IBIL measurements of LiF. The self-absorption effect would reduce the intensities of F3+ color centers because of the absorption of F-type centers at low temperatures, while the effect is weak at high temperatures due to the degradation of F-type centers.

Ion-Beam-Induced Luminescence of LiF Using Negative Ions

Negative ion-beam-induced luminescence (IBIL) measurements of a pure LiF crystal using 20 keV are performed to monitor the formation and annihilation of luminescence centers during ion irradiation. Several emission bands are observed in the IBIL spectra and the evolvement mechanisms of the corresponding centers are identified. The difference between the IBIL measurements using positive ions and negative ions is that the intensities of luminescence centers can reach the maxima at lower fluences under negative-ion irradiation due to free charge accumulation.

PARAFAC analysis of IBIL spectra from silver ion exchanged glasses

In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis to the investigation of Ion Beam Induced Luminescence (IBIL) spectra of Ag+↔Na+ ion exchanged silicate glasses, in order to check the possibility to obtain additional information on the formation of silver aggregates under ion irradiation by a proper statistical rearrangement of experimental spectra. We decomposed the data by PARAFAC taking into account both IBIL emission features and their evolution as a function of the time. Shape and trend under irradiation of the extracted components were correlated to silver concentration and aggregates in the investigated systems. Strength and weakness of this statistical approach applied to IBIL spectra recorded as a function of time were evidenced and discussed.

Ionoluminescence of fused silica under swift ion irradiation

Ion beam induced luminescence spectra have been in-situ recorded during He+ (2.5MeV), O4+ (13.5MeV) and Si4+ (24.4MeV) irradiations for three vitreous silica grades with different OH content (KU1, KS-4V and Infrasil 301). Remarkable changes in the ionoluminescence spectra of the three silica grades were observed for low ion fluences. He+ irradiated samples exhibited higher luminescence than equivalent ones irradiated with heavier O4+ and Si4+ ions. KU1 samples with the highest OH content showed the lowest blue luminescence. Blue luminescence maximum during ion irradiations with O4+ and Si4+ ions is correlated with structural changes.

Study of the ionoluminescence behavior of the gemstones: Beryl (aquamarine variety), opal, and topaz

Ion beam induced luminescence (IBIL) is introduced as a powerful luminescence technique for analyzing the gemstones. Although IBIL is basically comparable to cathodoluminescence (CL), as a well-known luminescence method for studying the gemstones, its high energy density, superior flexibility in depth resolving and fast ionization rate, qualify it for studying weakly luminescent, multi-layer, and precious samples. In order to examine the potential of IBIL in analyzing the gemstones, three samples of beryl (aquamarine variety), opal, and topaz, with different luminosities, were studied through simulations and experiments. The results of the Monte Carlo simulations of the proton beam in interaction with the mentioned gemstones, displayed the capabilities of IBIL, especially in comparison to the well-known technique of CL. The in-air ion beam induced luminescence experiments of the natural samples were performed at room temperature. Also, the complementary technique of microPIXE was applied for elemental analyses of the samples. The promising results of the IBIL experiments exhibit the ability of the technique for analyzing weakly luminescent gemstones, such as aquamarine. The IBIL spectra also exhibit some unknown luminescence bands, which are mostly located in the UV part of the spectra. These new bands disclose the existence of the unknown luminescence activators in the samples. Possible ideas on the origins of these new bands are proposed.

Continuous observation of ion beam induced luminescence spectra from organic standard targets

Ion beam induced luminescence (IBIL) analysis was performed on organic targets are typical organic contaminants in aerosols. An external proton microbeam with an energy of 3 MeV was selected as the probe for the continuous IBIL measurement. Commercially available organic standards, including common amino acids (nicotinamide adenine dinucleotide, riboflavin and tryptophan) and a polycyclic aromatic hydrocarbon (benzo[a]pyrene), were used to test the analysis. Differences in chemical composition were distinguished by the shape of the IBIL spectrum in the UV/visible/near-IR region (200–900 nm). The IBIL spectrum changed as the proton irradiation damage increased. These results suggest that qualitative characterization of organic materials might be possible through the continuous measurement of IBIL spectra.

Ion Beam Induced Luminescence capabilities for the analysis of coarse-grained river sediments

In this work the Ion Beam Induced Luminescence (IBIL) capabilities for the analysis of geological mobile sediment samples from the beds of three major rivers flowing in the Veneto Region (North-Eastern Italy) is presented in the first application of this technique to characterize such samples. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) spectra were also measured and discussed to give indications for the identification of the main luminescence features. The evolution of the different IBIL components with the irradiation dose was studied and their correlation to matrix defects outlined. Finally, a Principal Component Analysis (PCA) of the IBIL evolving spectra was performed to verify the capability of this approach to discriminate among the different samples.