¹⁸O/¹⁶O isotopic separation in anodic tantala films by glow discharge time‐of‐flight mass spectrometry

Abstract

Glow discharge mass spectrometry has been widely used for trace and ultra-trace element analysis of high-purity alloys. A novel pulsed radio frequency glow discharge time-of-flight mass spectrometer (rf GD TOFMS) has been developed that retains the pulsed radio frequency analytical ion source to provide ion signal enhancement due to processes involving Penning ionisation. A time-resolved detection mode has been implemented to sample the afterglow regime of the pulse profile, corresponding to the highest ion signal intensities. Here, the performance of rf GD TOFMS in isotope differentiation is discussed. Anodic tantala films, comprising 18 O-rich layers of controlled thicknesses and locations, were formed by appropriate combination of anodising of tantalum in electrolytes enriched with 18 O isotopes and of natural O isotopic abundance. Transmission electron microscopy (TEM) and radio frequency glow discharge optical emission spectrometry (rf GD OES) analyses were performed to examine the morphology and elemental distributions of the specimens, while the content of 18

Influence of the hydrogen contained in amorphous silicon thin films on a pulsed radiofrequency argon glow discharge coupled to time of flight mass spectrometry. Comparison with the addition of hydrogen as discharge gas

“…Recently, the analytical capabilities of rf-PGD-ToFMS have been successfully investigated for depth profile analysis of nanostructured materials, 12 polymers, 13 implanted silicon 14 and anodic tantala films. 15 It is well known that the hydrogen content on high quality intrinsic and doped a-Si:H thin films is around 10%. 4 It has been previously reported that the addition of hydrogen to Ar GD seriously affects the intensity of the analytes and reduces the sputtering rate.…”

Detection of negative ions in glow discharge mass spectrometry for analysis of solid specimens

“…An ideal material for testing and evaluation is anodic tantala [17]. Anodic tantala films may be formed in a very wide range of electrolytes, allowing incorporation of appropriate species.…”

[sup 18]O Tracer Study of Porous Film Growth on Aluminum in Phosphoric Acid

“…[6][7][8][9] Secondary-ion mass spectrometry and time of flight glow discharge mass spectrometry may also be employed with sputtering of the oxide layers or imaging of oxide cross sections. [10][11][12][13][14][15][16] In the present work, 18 O tracer is used with NRA to investigate the formation of porous films on aluminum under mild anodizing conditions. Porous anodic films have been studied extensively due to their importance in the protection of aluminum alloys 17 and, more recently, for various nanotechnological applications.…”