The Distribution of Phosphorus in Romano-British Ironwork

1990 ◽  
Vol 185 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Robert M. Ehrenreich

AbstractPhosphorus is found to be a common impurity in many of the iron tools and weapons produced during the pre-Roman and Roman Iron Ages of Britain (600 BC - 300 AD). The effects of this impurity on the properties and performance of antiquarian materials is not well understood, however. This paper presents the initial findings of an in-depth study of the distribution, chemistry, and effects of phosphorus in Romano-British ironwork. For this purpose, two Romano-British iron artifacts from the site of Ircheoter, Northamptonshire, were examined using powerful techniques for archeological materials analysis that include electron microprobe, secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM) with energydispersive x-ray spectroscopy capabilities (EDXS), and Auger electron spectroscopy (AES). It was found that phosphorous was indeed present in the artifacts. The phosphorus atoms were predominantly segregated at grain boundaries and thus should have led to a lowering of grain boundary cohesion and a degradation in the performance of the tools.

1993 ◽  
Vol 316 ◽  
Author(s):  
Rabi S. Bhattacharya ◽  
A.K. Rai

ABSTRACTThe feasibility of strength and reliability improvements of Si3N4 through ion implantations has been studied. The approach has been to implant elements that may chemically combine with themselves to form precipitates after appropriate annealing. These precipitates can improve the strength and reliability of ceramics through the introduction of a compressive stress in the implanted surface layer and/or by modifying the fracture originating machining flaws. Sequential implantations of ion pairs of Ti+ and C+, and Si+ and C+ were performed at energies in the range 46 to 175 keV and at doses of 1×1017 cm-2 for each ion species. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM) techniques were used to analyze the implanted layer. Strength and reliability were determined from four-point flexure strength measurements. Precipitates of TiN and C were found to form in Ti++C+ and Si++C+ implanted Si3N4 surfaces, respectively. Si++C+ implantation resulted in improvements of both strength and reliability of Si3N4, while Ti++C+ implantations had no effect.


1995 ◽  
Vol 10 (7) ◽  
pp. 1790-1794 ◽  
Author(s):  
Kyu Ho Park ◽  
Cha Yeon Kim ◽  
Young Woo Jeong ◽  
Hyun Ja Kwon ◽  
Kwang Young Kim ◽  
...  

The microstructural variation and the interdiffusion of Pt (80 nm)/Ti (70 nm)/SiO2/Si during annealing in O2 were investigated using Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. While the as-deposited and 400 °C annealed samples showed well-defined layer structures without any significant interfacial reaction, the degree of oxidation remarkably increased with increasing temperature above 500 °C. The PtTi alloy phase with Pmma structure (AuCd type) was observed from the 500 °C annealed sample. Drastic interdiffusion occurring above 600 °C changed the Pt/Ti bilayer into a very entangled structure. Some TiO2 phases were exposed to the ambient between Pt hillocks. In addition, a small amount of Pt-silicide was found near the TiOx/SiO2 interface.


1987 ◽  
Vol 102 ◽  
Author(s):  
M. Genut ◽  
M. Eizenberg

ABSTRACTModifications in the course of reaction between Co thin films and single crystal GaAs substrate due to the addition of a Ge film either on top or below the metal layer have been studied. The microstructure and phase formation for the systems: Co/GaAs, Co/Ge/GaAs, and Ge/Co/GaAs have been studied by Auger electron spectroscopy, transmission electron microscopy and X-ray diffraction.


1996 ◽  
Vol 11 (1) ◽  
pp. 229-235 ◽  
Author(s):  
E. Cattaruzza ◽  
R. Bertoncello ◽  
F. Trivillin ◽  
P. Mazzoldi ◽  
G. Battaglin ◽  
...  

Silica glass was implanted with chromium at the energy of 35 and 160 keV and at fluences varying from 1 × 1016 to 11 × 1016 ions cm−2. In a set of chromium-implanted samples significant amounts of carbon were detected. Samples were characterized by x-ray photoelectron spectroscopy, x-ray-excited Auger electron spectroscopy, secondary ion mass spectrometry, and Rutherford backscattering spectrometry. Chromium silicide and chromium oxide compounds were observed; the presence of carbon in the implanted layers induces the further formation of chromium carbide species. Thermodynamic considerations applied to the investigated systems supply indications in agreement with the experimental evidences.


1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.


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