Ion Beam Sputtering Stress-Free Physical Process
Conventional mechanical polishing or cutting techniques on soft and composite materials apply significant lateral sheer forces to the sample and often result in cross section surface artefacts such as scratches, smearing, wash-out of softer materials, delamination and other damage.
In contrast, Sage Analytical Lab’s ion beam sputtering is a stress-free physical process whereby atoms are ejected from a target material due to bombardment of the target by energetic particles.
Mirror-surface quality cross sections are formed by placing an ion beam resistant mask in such way onto a sample surface that one half of the vertically incident ion beam is blocked by the mask. The other half of the ion beam gradually removes the sample material protruding from the mask, so that a straight cross sectional plain is formed below the edge of the protective mask.
The range of materials and samples applicable to ion cross section milling is not limited to hard matter; even “soft” samples such as paper, polymers, and even powders allow high-quality sectioning in the IM4000.
Sage’s flatmilling describes the uniform ion-beam induced polishing of sample surfaces as large as 5mm in diameter. Such wide uniformly polished areas can be achieved as the sample rotation (or swing) center axis is shifted from the ion beam center, thereby compensating the ion beam profile intensity distribution.
A variable beam incidence angle (freely selectable from vertical to glancing incidence) allows both, a perfect smoothing – e.g. as preparation for EBSD analysis – or a selective enhancement of specimen surface features (relief milling) for optimized SEM observation.
Optionally, IM4000 offers the possibility to observe the cross section cutting area live through a window in the processing chamber using a high-resolution optical microscope. This supports the user e.g. in deciding the end point of the sample milling in case of unknown materials.