A universal ion-beam-sputtering device for diffusion studies

Abstract

An apparatus for ion-beam-sputtering is described which offers for the first time the possibility of measuring radiotracer diffusion profiles with mean diffusion length (Dt) 1/2 (D is the tracer diffusion coefficient and t is the diffusion time) in the nano-as well as in the micrometre range. It is also possible to use the device for ion milling, especially for the deposition of thin layers of radiotracer onto diffusion samples. Investigations of diffusion in pure metals, in a metallic glass, in a compound semiconductor and in intermetallic compounds are presented as examples.

Niobium and titanium diffusion in the high niobium-containing Ti–54Al–10Nb alloy

“…The sputtering device developed by Wenwer et al [21] was used. Sputtering was performed in a highvacuum chamber using Ar C ions with the energy of 1.1 keV and a beam current of 20 mA.…”

Diffusion Experiment in Lithium Ionic Conductors with the Radiotracer of 8Li

“…Therefore, the temporal evolution of α-particle yields that come out of the sample would be a measure of the diffusivity of Li. It should be noted that the present diffusion time is different from that of the conventional radiotracer method for diffusion studies (Wenwer at al., 1996) because the tracer in the present method diffuses all the time of the measurement. This is the reason why we call the present method as a non-destructive on-line measurement of diffusion.…”

“…Conventional diffusion studies by means of the radiotracer method in conjunction with a serial sectioning technique have been performed as follows (Wenwer at al., 1996): A small amount of a suitable radioactive isotope of the diffusing element is deposited onto the sample surface of interest. After a diffusion annealing at a temperature of T for a time of t, the sample is sectioned in parallel to the initial surface.…”

Diffusion in Metallic Glasses and Supercooled Melts

“…Gupta et al (1975) were probably the first who applied rf sputter sectioning to study diffusion in an amorphous alloy. Up-to-date devices for serial sectioning of radioactive diffusion samples by ion-beam sputtering are described, for example, by Faupel et al (1992) and Wenwer et al (1996). Sectioning of shallow diffusion zones, which correspond to diffusion lengths between several tens of nm and several m, is possible by employing ion-beam sputtering.…”