Electrostatic force: A novel method for mounting small zircon grains to expose the maximum outer surface

Abstract

Mirco-beam isotopic analyses of zircon have increased dramatically with applications for providing multi-isotopic information. As small as 2–5 μm spot size could be used by secondary ion mass spectrometry for in-situ isotope analysis of zircon with high precision and accuracy. However, this lateral spatial resolution is still difficult to measure <5 μm rims of zircon in a traditional sample mount, because of the relief at the epoxy-grain interface and possible contamination from double-sided tape. These shortcomings hinder the research for low temperature metamorphism or fluid events, which usually forms very thin rim on previous zircon. To expose the outermost layer of zircon grains on the mount surface is the best way to measure the outer thin rims. We present a new method for sample preparation based on electrostatic force to replace the double-sided tape for fixing zircon grains. The new procedure achieves a flat and smooth surface and exposes the outermost layer of each zircon grain on the mount surface. The possible contamination from the tape can be avoided. This method can be applied to obtain depth profiles from outer layer of zircon grains crystallized under a wide variety of geological conditions.

Keywords

• Secondary ion mass spectrometry
• Electrostatic force
• Zircon
• Surface analysis
• Sample preparation