Dual-Beam Scanning Electron Microscope (SEM) and Focused Ion Beam (FIB): A Practical Method for Characterization of Smal
- PDF / 887,780 Bytes
- 15 Pages / 612 x 792 pts (letter) Page_size
- 4 Downloads / 224 Views
Dual-Beam Scanning Electron Microscope (SEM) and Focused Ion Beam (FIB): A Practical Method for Characterization of Small Cultural Heritage Objects Matthew Carl, Chris A. Smith, and Marcus L. Young Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203-5017, U.S.A. ABSTRACT Knowledge of the composition of many cultural heritage objects is limited, resulting in many unanswered questions in regards to the provenance, composition, and production methods. In this paper, our objective is to show that dual beam scanning electron microscope (SEM) and focused ion beam (FIB) can be used rapidly and non-destructively to determine the surface and bulk metal compositions in small cultural heritage objects. We show, for the first time, that this novel FIB technique can be successfully applied non-destructively to cultural heritage objects by examining three representative silver plated objects (Candelabra, “Century” spoon, and New York World’s Fair spoon) from the Dallas Museum of Art’s unparalleled collection of modern American silver. In each case, we successfully reveal and characterize the bulk metal as well as the Ag-plating, up to ~80 µm deep and show that there is no visual damage resulting from the milling process of the FIB. This novel characterization technique can be applied, due to its ease of availability and rapid use, to many other problems in addition to silver plated objects, making dual beam SEM/FIB a possible cornerstone technique in the study of cultural heritage objects. INTRODUCTION Scientific studies of historical and cultural heritage objects are focused on determining the provenance, condition, and manufacturing technologies of the people who produced them [113]. One major challenge of studying heritage objects is that they must be non-destructively and non-invasively examined, often requiring a combination of analytical techniques for full characterization. Analytical techniques, such as conventional X-ray diffraction (XRD) and X-ray fluorescence (XRF) allow for surface studies of the objects, but cannot properly examine the bulk material; furthermore, these surface studies can be misleading since many objects have surface alterations such as corrosion layers, tarnishes, patinas, plating, and post-excavation cleaning residues [4-11]. Studies of the bulk material can be performed non-destructively using synchrotron, neutron, and proton sources available at large user facilities; however, it is difficult to examine large bodies of work due to the nature of these facilities [12-15]. Our initial study is focused on the Jewel Stern American Silver Collection at the Dallas Museum of Art (DMA) which contains over 400 Ag and Ag-plate objects from the Modernist movement of the late 19th and early 20th centuries [16]. The DMA has an important collection of 20th century American silver and silver-plated objects and houses one of the most comprehensive collections of 19th and 20th century silver objects. The bulk metal and plating compositions and processing are not well doc
Data Loading...
