The universal sample holders of microanalytical instruments of FIB, TEM, NanoSIMS, and STXM-NEXAFS for the coordinated analysis of extraterrestrial materials

Abstract

We developed universal sample holders [the Kochi grid, Kochi clamp, and Okazaki cell) and a transfer vessel (facility-to-facility transfer container (FFTC)] to analyze sensitive and fragile samples, such as extremely small extraterrestrial materials. The holders and container prevent degradation, contamination due to the terrestrial atmosphere (water vapor and oxygen gas) and small particles, as well as mechanical sample damage. The FFTC can isolate the samples from the effects of the atmosphere for more than a week. The Kochi grid and clamp were made for a coordinated micro/nano-analysis that utilizes a focused-ion beam apparatus, transmission electron microscope, and nanoscale secondary ion mass spectrometry. The Okazaki cell was developed as an additional attachment for a scanning transmission X-ray microscope that uses near-edge X-ray absorption fine structure (NEXAFS). These new apparatuses help to minimize possible alterations from the exposure of the samples to air. The coordinated analysis involving these holders was successfully carried out without any sample damage or loss, thereby enabling us to obtain sufficient analytical datasets of textures, crystallography, elemental/isotopic abundances, and molecular functional groups for µm-sized minerals and organics in both the Antarctic micrometeorite and a carbonaceous chondrite. We will apply the coordinated analysis to acquire the complex characteristics in samples obtained by the future spacecraft sample return mission.

A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

“…Chambers A and C contain samples collected from the first and second touchdown sites (TD1 and TD2), respectively. Air-tight sample transfer holders 55 were used to bring samples from JAXA to Kyoto University. The allocated grains were handled in an N 2 -filled glove box at Kyoto University.…”

A history of mild shocks experienced by the regolith particles on hydrated asteroid Ryugu

“…cataloguing and preliminary analysis at the JAXA curation facility, eight particles up to 4.1 mm in size were allocated to the phase 2 curation Kochi team for in-depth investigations. An airtight sample transport vessel with a sample capsule pack made of sapphire glass and stainless steel 60 was used to avoid terrestrial contaminants during sample transportation among institutes. The particles were polished under dry conditions to avoid the elution of any material from the surface during polishing.…”

“…After the deposition of tungsten protection layers, regions of interest (up to ~25 × 25 µm 2 ) were cut out and thinned using a Ga + ion beam at an accelerating voltage of 30 kV and then, finalized at 5 kV and a probe current of 40 pA to minimize surface ion-damage layers. Subsequently, the ultrathin sections were mounted on scaled-up Cu grids (Kochi grid 60 ) using a micromanipulator equipped with an FIB.…”

Chemical and elemental mapping of spent nuclear fuel sections by soft X-ray spectromicroscopy

“…Although the FIB sections produced are relatively uniform in thickness, defects like voids and cracks present in the sample before FIB sectioning offer interesting points for investigation and useful references for image alignment, which is crucial for STXM analysis. FIB sections have been studied on a variety of samples from environmental (Benzerara et al, 2007) to archeological (Michelin et al, 2013;Bernard et al, 2009Bernard et al, , 2007 to interplanetary (Yabuta et al, 2014;Uesugi et al, 2014;Ito et al, 2020;Gu et al, 2020). FIB sections have also been used to study spent nuclear fuel recently (Clark et al, 2020;Kessler et al, 2020;Yuan et al, 2021;Liu et al, 2021;Teague & Gorman, 2014;Degueldre et al, 2016;Degueldre & Veleva, 2014).…”