A novel apparatus for in situ compression of submicron structures and particles in a high resolution SEM

Abstract

We report on the development and characterization of a novel in situ manipulation device to perform stressing experiments on the submicron scale inside a high resolution field emission scanning electron microscope. The instrument comprises two main assembly groups: an upper part for positioning and moving a mounted probe and a force sensor as well as a specimen support as lower part. The upper part consists of a closed loop tripod piezoelectric scanner mounted on a self-locking coarse positioning stage. Two interlocked steel springs and a linear variable differential transformer measuring the springs’ deflections compose the lower part of the instrument. This arrangement acts as force-sensor and sample support. In comparison to already well-established concepts a wide measuring range is covered by adjusting the spring constant between 30 N/m and 50000 N/m. Moreover, the new device offers striking advantages with respect to force calibration and sample deformation measurements. Force calibration is performed using the eigenfrequency of the force detection system directly inside the SEM. Deformation data are obtained with high accuracy by simultaneously recording displacements above and below the specimen. The detrimental apparatus compliance is determined, and the influence on measured data subsequently minimized: an easy to validate two-springs-in-series model is used for data correction. A force resolution in normal direction of 100 nN accompanied by a sample deformation resolution of 5 nm can be achieved with the instrument using an appropriate load cell stiffness. The capabilities and versatility of this instrument are exemplified by compression experiments performed on submicron amorphous silica particles.

A Novel Approach for Preparation and In Situ Tensile Testing of Silica Glass Membranes in the Transmission Electron Microscope

“…Also in this case, the E values of 21 and 45 GPa are significantly lower than the value known for bulk fused silica (72-76 GPa) (Adachi and Sakka, 1990). However, they are typical for such SFB-type silica particles, as reported for sol-gel-derived hollow silica spheres and silica microcapsules by Zhang et al (2009Zhang et al ( , 2010 and submicron-sized silica spheres by Romeis et al (2012Romeis et al ( , 2014 and Paul et al (2015), respectively. In difference to this, Romeis et al (2014) and Paul et al (2015) reported E values of 71 ± 1.4 GPa for heat-treated SFB-type silica spheres approaching the values known for bulk fused silica (72-76 GPa) (Adachi and Sakka, 1990).…”

“…In the present study, the PI95 holder was operated under displacement control, while experiments are carried out with and without e-beam irradiation. In our previous studies on nanoscale silica spheres, we noticed a strong impact of e-beam irradiation on their mechanical behavior inside the TEM (Mačković et al, 2014 and SEM (Romeis et al, 2012). Similarly, in the present work, the impact of e-beam irradiation was investigated in case of silica glass.…”

“…Iwata and Nishi (2008) demonstrated that irradiation of silica glass with electrons results in an increased impact value (obtained from standard Charpy impact tests) due to an increase in the bonding energy for the silicon-oxygen atomic pairs in the atomic network structure of silica glass. Several approaches have demonstrated that sol-gelderived nanoscale silica spheres exhibit an enormous ductility if compressed under moderate electron beam (e-beam) irradiation inside the transmission electron microscope (TEM) (Zheng et al, 2010;Mačković et al, 2014Mačković et al, , 2016 and scanning electron microscope (SEM) (Romeis et al, 2012;Stauffer et al, 2014;Bhowmick et al, 2015). In contrast, nanoscale vitreous silica spheres (heat-treated Stöber-Fink-Bohn (SFB)-type silica (Stöber et al, 1968;Hanisch et al, 2012)) fracture in brittle manner if compressed in the absence of e-beam irradiation inside the SEM and TEM (Romeis et al, 2014Paul et al, 2015).…”

Local densification of a single micron sized silica sphere by uniaxial compression

“…Uniaxial compression of the single silica particle is performed by a SEM supported in situ manipulator [23]. After a transfer and alignment procedure, ex situ Raman spectroscopy gives access to the local structure of the deformed glass particle [13]: significant densification (about 11%) is found near the deformed contacts; the inner parts of the particle are essentially non-densified.…”

“…Particle compression in the SEM supported micromanipulator [23] was performed between a diamond flat punch indenter and a (100) silicon wafer. The displacement rate of the indenter was 200 nm/s; force-and deformation resolutions were 1-10 lN and 5 nm.…”