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Simpson R, Varney TL, Coulthard I, Swanston T, Grimes V, Munkittrick TJA, Jankauskas R, Cooper DML. Insights into biogenic and diagenetic lead exposure in experimentally altered modern and archaeological bone: Synchrotron radiation X-ray fluorescence imaging. Sci Total Environ 2021; 790:148144. [PMID: 34111788 DOI: 10.1016/j.scitotenv.2021.148144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/25/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Bones represent a valuable biological archive of environmental lead (Pb) exposure for modern and archaeological populations. Synchrotron radiation X-ray fluorescence imaging (SR-XFI) generates maps of Pb in bone on a microstructural scale, potentially providing insights into an individual's history of Pb exposure and, in the context of archaeological bone, the biogenic or diagenetic nature of its uptake. The aims of this study were to (1) examine biogenic spatial patterns for Pb from bone samples of modern cadavers compared with patterns observed archaeologically, and (2) test the hypothesis that there are spatial differences in the distribution of Pb for diagenetic and biogenic modes of uptake in bone. To address these aims, this study used inductively coupled plasma-mass spectrometry (ICP-MS) and SR-XFI on unaltered and experimentally altered cadaveric bone samples (University of Saskatchewan, Saskatoon, SK) and archaeological bone samples from 18th to 19th century archaeological sites from Antigua and Lithuania. Bone concentrations of modern individuals are relatively low compared to those of archaeological individuals. SR-XFI results provide insights into modern Saskatchewan Pb exposure with some samples demonstrating a pattern of relatively low Pb exposure with higher levels of Pb exposure occurring in bone structures of a relatively older age that formed earlier in life, likely during the era of leaded gasoline (pre-1980s), and other samples demonstrating a pattern of fairly consistent, low-level exposure. Results support hypotheses for the spatial distribution of Pb corresponding to biogenic vs. diagenetic uptake. Diagenetic Pb is mainly confined to the periosteal surface of each sample with some enrichment of cracks and sub-periosteal canals. This may be useful in the future for differentiating diagenetic from biogenic Pb accumulation, analyzing environmental contamination, and informing sampling strategies in archaeological or fossil bone.
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Affiliation(s)
- Rachel Simpson
- Department of Archaeology and Anthropology, University of Saskatchewan, 55 Campus Drive, Saskatoon S7N 5B1, SK, Canada.
| | - Tamara L Varney
- Department of Anthropology, Lakehead University, 955 Oliver Road, Thunder Bay P7B 5E1, ON, Canada.
| | - Ian Coulthard
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon S7N 2V2, SK, Canada.
| | - Treena Swanston
- Department of Anthropology, Economics, Political Science, MacEwan University, 10700 104 Avenue NW, Edmonton T5J 4S2, AB, Canada; Department of Biological Sciences, MacEwan University, 10700 104 Avenue NW, Edmonton T5J 4S2, AB, Canada.
| | - Vaughan Grimes
- Department of Archaeology, Memorial University, 210 Prince Philip Drive, St. John's A1C 5S7, NL, Canada; Department of Earth Sciences, Memorial University, 9 Arctic Avenue, St. John's A1B 3X5, NL, Canada.
| | - T Jessica A Munkittrick
- Department of Archaeology, Memorial University, 210 Prince Philip Drive, St. John's A1C 5S7, NL, Canada.
| | - Rimantas Jankauskas
- Department of Anatomy, Histology and Anthropology, Vilnius University, M.K. Ciurlionio str. 21, Vilnius, LT-03101, Lithuania.
| | - David M L Cooper
- Department of Anatomy, Physiology, and Pharmacology, University of Saskatchewan, 107 Wiggins Road, Saskatoon S7N 5E5, SK, Canada.
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Simpson R, Cooper DML, Swanston T, Coulthard I, Varney TL. Historical overview and new directions in bioarchaeological trace element analysis: a review. Archaeol Anthropol Sci 2021; 13:24. [PMID: 33520004 PMCID: PMC7810633 DOI: 10.1007/s12520-020-01262-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 12/14/2020] [Indexed: 05/08/2023]
Abstract
Given their strong affinity for the skeleton, trace elements are often stored in bones and teeth long term. Diet, geography, health, disease, social status, activity, and occupation are some factors which may cause differential exposure to, and uptake of, trace elements, theoretically introducing variability in their concentrations and/or ratios in the skeleton. Trace element analysis of bioarchaeological remains has the potential, therefore, to provide rich insights into past human lifeways. This review provides a historical overview of bioarchaeological trace element analysis and comments on the current state of the discipline by highlighting approaches with growing momentum. Popularity for the discipline surged following preliminary studies in the 1960s to 1970s that demonstrated the utility of strontium (Sr) as a dietary indicator. During the 1980s, Sr/Ca ratio and multi-element studies were commonplace in bioarchaeology, linking trace elements with dietary phenomena. Interest in using trace elements for bioarchaeological inferences waned following a period of critiques in the late 1980s to 1990s that argued the discipline failed to account for diagenesis, simplified complex element uptake and regulation processes, and used several unsuitable elements for palaeodietary reconstruction (e.g. those under homeostatic regulation, those without a strong affinity for the skeleton). In the twenty-first century, trace element analyses have been primarily restricted to Sr and lead (Pb) isotope analysis and the study of toxic trace elements, though small pockets of bioarchaeology have continued to analyse multiple elements. Techniques such as micro-sampling, element mapping, and non-traditional stable isotope analysis have provided novel insights which hold the promise of helping to overcome limitations faced by the discipline. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12520-020-01262-4.
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Affiliation(s)
- Rachel Simpson
- Department of Archaeology and Anthropology, University of Saskatchewan, Saskatoon, SK Canada
- Present Address: Department of Anthropology, University of Alberta, Edmonton, AB Canada
| | - David M. L. Cooper
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK Canada
| | - Treena Swanston
- Department of Anthropology, Economics and Political Science, MacEwan University, Edmonton, AB Canada
- Department of Biological Sciences, MacEwan University, Edmonton, AB Canada
| | | | - Tamara L. Varney
- Department of Anthropology, Lakehead University, Thunder Bay, ON Canada
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I. Eyeing the past: synchrotron µ-XANES and XRF imaging of tarnish distribution on 19th century daguerreotypes. J Synchrotron Radiat 2019; 26:1679-1686. [PMID: 31490159 DOI: 10.1107/s1600577519006313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/03/2019] [Indexed: 06/10/2023]
Abstract
Louis-Jacques-Mandé Daguerre introduced the first successful photographic process, the daguerreotype, in 1839. Tarnished regions on daguerreotypes supplied by the National Gallery of Canada were examined using scanning electron microscopy energy-dispersive X-ray spectroscopy and synchrotron-radiation analysis. Synchrotron X-ray fluorescence imaging visualized the distribution of sulfur and chlorine, two primary tarnish contributors, and showed that they were associated with the distribution of image particles on the surface. X-ray absorption near-edge structure spectroscopy determined the tarnish to be primarily composed of AgCl and Ag2S. Au2S, Au2SO4, HAuCl4 and HgSO4 were also observed to be minor contributors. Environmental contamination may be a source of these degradation compounds. Implications of these findings will be discussed.
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Affiliation(s)
- M S Kozachuk
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - T K Sham
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - R R Martin
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - A J Nelson
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - I Coulthard
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I, McElhone JP. Author Correction: Recovery of Degraded-Beyond-Recognition 19th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission. Sci Rep 2018; 8:12158. [PMID: 30089846 PMCID: PMC6082915 DOI: 10.1038/s41598-018-30576-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Swanston T, Varney TL, Kozachuk M, Choudhury S, Bewer B, Coulthard I, Keenleyside A, Nelson A, Martin RR, Stenton DR, Cooper DML. Franklin expedition lead exposure: New insights from high resolution confocal x-ray fluorescence imaging of skeletal microstructure. PLoS One 2018; 13:e0202983. [PMID: 30138435 PMCID: PMC6107236 DOI: 10.1371/journal.pone.0202983] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/13/2018] [Indexed: 11/20/2022] Open
Abstract
In the summer of 1845, under the command of Sir John Franklin, 128 officers and men aboard Royal Navy ships HMS Erebus and HMS Terror sailed into Lancaster Sound and entered the waters of Arctic North America. The goal of this expedition was to complete the discovery of a northwest passage by navigating the uncharted area between Barrow Strait and Simpson Strait. Franklin and his crew spent the first winter at Beechey Island, where three crewmen died and were buried. In September 1846, the ships became stranded in ice off the northwest coast of King William Island, where they remained until April 1848. At that time, the crew, reduced to 105, deserted the ships and retreated south along the island's western and southern shores in a desperate attempt to reach the mainland and via the Back River, to obtain aid at a Hudson's Bay Company Post. Sadly, not one individual survived. Previous analyses of bone, hair, and soft tissue samples from expedition remains found that crewmembers' tissues contained elevated lead (Pb) levels, suggesting that Pb poisoning may have contributed to their demise; however, questions remain regarding the timing and degree of exposure and, ultimately, the extent to which the crewmembers may have been impacted. To address this historical question, we investigated three hypotheses. First, if elevated Pb exposure was experienced by the crew during the expedition, we hypothesized that those sailors who survived longer (King William Island vs. Beechey Island) would exhibit more extensive uptake of Pb in their bones and vice versa. Second, we hypothesized that Pb would be elevated in bone microstructural features forming at or near the time of death compared with older tissue. Finally, if Pb exposure played a significant role in the failure of the expedition we hypothesized that bone samples would exhibit evidence of higher and more sustained uptake of Pb than that of a contemporary comparator naval population from the 19th century. To test these hypotheses, we analyzed bone and dental remains of crew members and compared them against samples derived from the Royal Navy cemetery in Antigua. Synchrotron-based high resolution confocal X-ray fluorescence imaging was employed to visualize Pb distribution within bone and tooth microstructures at the micro scale. The data did not support our first hypothesis as Pb distribution within the samples from the two different sites was similar. Evidence of Pb within skeletal microstructural features formed near the time of death lent support to our second hypothesis but consistent evidence of a marked elevation in Pb levels was lacking. Finally, the comparative analysis with the Antigua samples did not support the hypothesis that the Franklin sailors were exposed to an unusually high level of Pb for the time period. Taken all together our skeletal microstructural results do not support the conclusion that Pb played a pivotal role in the loss of Franklin and his crew.
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Affiliation(s)
- Treena Swanston
- Department of Anthropology, Economics and Political Science, MacEwan University, Edmonton, Alberta, Canada
- Department of Biological Sciences, MacEwan University, Edmonton, Alberta, Canada
| | - Tamara L. Varney
- Department of Anthropology, Lakehead University, Thunder Bay, Ontario, Canada
| | - Madalena Kozachuk
- Department of Chemistry, Western University, London, Ontario, Canada
| | - Sanjukta Choudhury
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Brian Bewer
- Canadian Light Source, Saskatoon, Saskatchewan, Canada
| | - Ian Coulthard
- Canadian Light Source, Saskatoon, Saskatchewan, Canada
| | - Anne Keenleyside
- Department of Anthropology, Trent University, Peterborough, Ontario, Canada
| | - Andrew Nelson
- Department of Chemistry, Western University, London, Ontario, Canada
- Department of Anthropology, Western University, London, Ontario, Canada
| | - Ronald R. Martin
- Department of Chemistry, Western University, London, Ontario, Canada
| | - Douglas R. Stenton
- Department of Anthropology, University of Waterloo, Waterloo, Ontario, Canada
| | - David M. L. Cooper
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I, McElhone JP. Recovery of Degraded-Beyond-Recognition 19 th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission. Sci Rep 2018; 8:9565. [PMID: 29934565 PMCID: PMC6015064 DOI: 10.1038/s41598-018-27714-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 06/05/2018] [Indexed: 11/22/2022] Open
Abstract
A daguerreotype image, the first commercialized photographic process, is composed of silver-mercury, and often silver-mercury-gold amalgam particles on the surface of a silver-coated copper plate. Specular and diffuse reflectance of light from these image particles produces the range of gray tones that typify these 19th century images. By mapping the mercury distribution with rapid-scanning, synchrotron-based micro-X-ray fluorescence (μ-XRF) imaging, full portraits, which to the naked eye are obscured entirely by extensive corrosion, can be retrieved in a non-invasive, non-contact, and non-destructive manner. This work furthers the chemical understanding regarding the production of these images and suggests that mercury is retained in the image particles despite surface degradation. Most importantly, μ-XRF imaging provides curators with an image recovery method for degraded daguerreotypes, even if the artifact’s condition is beyond traditional conservation treatments.
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Affiliation(s)
- Madalena S Kozachuk
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Tsun-Kong Sham
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.
| | - Ronald R Martin
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Andrew J Nelson
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.,The University of Western Ontario, The Department of Anthropology, 1151 Richmond Street, London, Ontario, N6A 5C2, Canada
| | - Ian Coulthard
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada.
| | - John P McElhone
- National Gallery of Canada, Musée des beaux-arts du Canada, 380 Sussex Drive, P.O. Box 427, Station A, Ottawa, Ontario, K1N 9N4, Canada
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Giffin KL, Swanston T, Coulthard I, Murphy AR, Cooper DML, Varney TL. Skeletal Lead Burden of the British Royal Navy in Colonial Antigua. Int J Osteoarchaeol 2017; 27:672-682. [PMID: 28919698 PMCID: PMC5574018 DOI: 10.1002/oa.2589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 02/13/2017] [Accepted: 03/11/2017] [Indexed: 05/23/2023]
Abstract
Lead (Pb) has been known to be a cause of human poisoning since ancient times, but despite this, it was a widely used metal in the European colonial period. In this study, the relationship between Pb exposure and the demographic variables ancestry and age was explored by comparing the bone Pb levels of individuals that were of either African or European ancestry, excavated from a British Royal Navy hospital cemetery (1793-1822 CE) at English Harbour in Antigua, West Indies. More direct comparisons of Pb levels between the two ancestral groups were possible in this study because of the unsegregated nature of this cemetery. Inductively coupled plasma mass spectrometry was used to determine bulk Pb levels in cortical bone samples from the fibular diaphyses of 23 male individuals. No significant difference was found between the distributions of the Pb levels of the ancestral groups (p = 0.94). Further, no positive correlations or significant differences were found in relation to the individuals' ages and their Pb levels (p = 0.24). Levels of Ba, Ca and rare earth elements support a largely biogenic origin of lead. This is bolstered by Pb deposition patterns, generated by synchrotron X-ray fluorescence imaging for another study. The data suggest that naval personnel, regardless of ancestry at English Harbour, had very similar experiences with regard to Pb exposure. Their exposure to the toxic metal was likely not consistent over time as steady exposure would have resulted in accumulation of Pb with age. This study contributes to addressing historical questions regarding the prevalence of Pb poisoning within the British Royal Navy during the colonial period.
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Affiliation(s)
- K. L. Giffin
- Department of AnthropologyLakehead UniversityThunder BayONCanada
| | - T. Swanston
- Department of Anthropology, Economics, and Political Science and the Department of Biological SciencesMacEwan UniversityEdmontonABCanada
| | | | - A. R. Murphy
- National Parks Antigua and BarbudaAntiguaAntigua and Barbuda
| | - D. M. L. Cooper
- Department of Anatomy and Cell BiologyUniversity of SaskatchewanSaskatoonSKCanada
| | - T. L. Varney
- Department of AnthropologyLakehead UniversityThunder BayONCanada
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Choudhury S, Thomas JK, Sylvain NJ, Ponomarenko O, Gordon RA, Heald SM, Janz DM, Krone PH, Coulthard I, George GN, Pickering IJ. Selenium preferentially accumulates in the eye lens following embryonic exposure: a confocal X-ray fluorescence imaging study. Environ Sci Technol 2015; 49:2255-2261. [PMID: 25607235 DOI: 10.1021/es503848s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Maternal transfer of elevated selenium (Se) to offspring is an important route of Se exposure for fish in the natural environment. However, there is a lack of information on the tissue specific spatial distribution and speciation of Se in the early developmental stages of fish, which provide important information about Se toxicokinetics. The effect of maternal transfer of Se was studied by feeding adult zebrafish a Se-elevated or a control diet followed by collection of larvae from both groups. Novel confocal synchrotron-based techniques were used to investigate Se within intact preserved larvae. Confocal X-ray fluorescence imaging was used to compare Se distributions within specific planes of an intact larva from each of the two groups. The elevated Se treatment showed substantially higher Se levels than the control; Se preferentially accumulated to highest levels in the eye lens, with lower levels in the retina, yolk and other tissues. Confocal X-ray absorption spectroscopy was used to determine that the speciation of Se within the eye lens of the intact larva was a selenomethionine-like species. Preferential accumulation of Se in the eye lens may suggest a direct cause-and-effect relationship between exposure to elevated Se and Se-induced ocular impairments reported previously. This study illustrates the effectiveness of confocal X-ray fluorescence methods for investigating trace element distribution and speciation in intact biological specimens.
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Affiliation(s)
- Sanjukta Choudhury
- Department of Geological Sciences, University of Saskatchewan , 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
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Woll AR, Agyeman-Budu D, Choudhury S, Coulthard I, Finnefrock AC, Gordon R, Hallin E, Mass J. Lithographically-fabricated channel arrays for confocal x-ray fluorescence microscopy and XAFS. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/493/1/012028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sham TK, Jiang DT, Coulthard I, Lorimer JW, Feng XH, Tan KH, Frigo SP, Rosenberg RA, Houghton DC, Bryskiewicz B. VUV- and Soft X-Ray-Induced Optical Luminescence and X-Ray Absorption Fine Structures of Porous Silicon. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-281-525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTOptical luminescence in porous silicon induced by soft X-ray and vacuum UV excitation with energies in the vicinity of the Si K-edge (1838 eV) and the Si L-edge (99 eV) has been observed. The luminescence has been used, together with total electron yield, to record X-ray absorption fine structure (XAFS) in the near-edge region of both Si edges. The near- edge spectra recorded simultaneously with either luminescence or total electron yield were compared, and the implications of these measurements for the structure of porous silicon are discussed.
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Coulthard I, Sham TK, Jiang DT, Tan KH. Synchrotron Radiation Induced Optical Luminescence from Porous Silicon: Recent Observations. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-452-547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractPhotoluminescence from porous silicon was examined using synchrotron radiation as an excitation source. The tunability of the excitation source permitted a wide range of excitation energies ranging from VUV to X-rays. This permitted site selective excitation where specific core levels (i.e. Si-K, O-K, Si-2p) were probed. In high porosity samples, luminescence bands of both surface and bulk origins were observed. All experiments exhibited a common luminescence maximum typically in the orange-red region of the visible spectrum. At certain specific excitation energies particularly in the VUV region additional peaks related to sites with oxygen character were also observed. The VUV excitation luminescence spectra of the porous silicon remarkably resembled that of oxygen deficient amorphous silicon dioxide glasses.
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Abstract
ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.
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Regier T, Paulsen J, Wright G, Coulthard I, Tan K, Sham TK, Blyth RIR. Commissioning of the Spherical Grating Monochromator Soft X-ray Spectroscopy Beamline at the Canadian Light Source. ACTA ACUST UNITED AC 2007. [DOI: 10.1063/1.2436101] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Heigl F, Lam S, Regier T, Coulthard I, Sham TK. Time-Resolved X-ray Excited Optical Luminescence from Tris(2-phenyl bipyridine)iridium [ J. Am. Chem. Soc. 2006, 128, 3906−3907]. J Am Chem Soc 2006. [DOI: 10.1021/ja069967e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Heigl F, Lam S, Regier T, Coulthard I, Sham TK. Time-Resolved X-ray Excited Optical Luminescence from Tris(2-phenyl bipyridine)iridium. J Am Chem Soc 2006; 128:3906-7. [PMID: 16551087 DOI: 10.1021/ja060243c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved X-ray Excited Optical Luminescence (TRXEOL) has been developed to investigate the optical properties of a green organometallic phosphor, tris(2-phenyl pyridine)iridium, Ir(ppy)3. Using time-gated measurements, we find that the characteristic luminescence band from a neat Ir(ppy)3 film is composed of a fast channel at approximately 534 nm and a slower channel at approximately 580 nm. The implication of this study and the applicability of the technique in the study of light emitting materials are noted.
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Affiliation(s)
- Franziskus Heigl
- Department of Chemistry, University of Western Ontario, London, Canada N6A 5B7
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Buckley AN, Hartmann AJ, Lamb RN, Stampfl APJ, Freeland JW, Coulthard I. Threshold Al KLL Auger spectra of oxidized aluminium foils. SURF INTERFACE ANAL 2003. [DOI: 10.1002/sia.1626] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zhu YJ, Coulthard I, Sham TK. XAFS studies of Rh nanostructures on porous silicon. J Synchrotron Radiat 1999; 6:529-531. [PMID: 15263369 DOI: 10.1107/s0909049599001235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/1998] [Accepted: 01/22/1999] [Indexed: 05/24/2023]
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Sham TK, Coulthard I. Edge-jump inversion in the Si L3,2-edge optical XAFS of porous silicon. J Synchrotron Radiat 1999; 6:215-216. [PMID: 15263253 DOI: 10.1107/s0909049599001314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/1998] [Accepted: 01/25/1999] [Indexed: 05/24/2023]
Affiliation(s)
- T K Sham
- Department of Chemistry, University of Western Ontario, London, Canada.
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Coulthard I, Degen S, Zhu YJ, Sham TK. Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures. CAN J CHEM 1998. [DOI: 10.1139/v98-146] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.
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