Double-tilting specimen holder cooled by liquid helium for JEM-4000EX

1992 ◽  
Vol 50 (2) ◽  
pp. 962-963
Author(s):  
H. Hashimoto ◽  
Y. Yokota ◽  
M. Hashimoto ◽  
E. Sukedai ◽  
H. Endoh ◽  
...  
Keyword(s):  
Low Temperature ◽  
Liquid Helium ◽  
Detection System ◽  
Atomic Scale ◽  
Driving Mechanism ◽  
Pole Piece ◽  
Present Specimen ◽  
Flowing Liquid ◽  
Specimen Holder ◽  
Electron Lens

For the study of phase transformation and structure change of crystals at low temperature in atomic scale, flowing liquid He specimen cooling holder has been constructed. It was aimed to achieve the low temperature without giving any effects to the resolution and analytical function of JEM-4000EX such as X-ray detection system and goniometer functions. The pole piece of electron lens used in this experiment has the following functions, i.e. Cs=2.88mm Cc=2.69mm f=3.55mm and the resolution is 0.34nm. The present specimen stage can be tilted ±20 degrees to X- and Y-directions inside of this pole piece. In connection of double tilt mechanism and protection of heat loss, double layered bellows are fabricated at the entrance of driving mechanism. At this point every vibrations from outside of the microscope such as from pumping out system of introduced liquid helium (the pipe A in Fig. 1) would be extinguished. This mechanism is fabricated in the vacuum box (marked by B in Fig.1).

A cathodoluminescence detection system for TEM/STEM

1983 ◽  
Vol 41 ◽  
pp. 146-147
Author(s):  
N. Yamamoto ◽  
J.C.H. Spence ◽  
D. Hazelton ◽  
A. Higgs ◽  
M. Bergh
Keyword(s):  
Detection System ◽  
Major Axis ◽  
Maximum Amount ◽  
Minor Axis ◽  
Pole Piece ◽  
Light Collection ◽  
Specimen Holder ◽  
Ellipsoidal Mirror ◽  
Detection Instrument ◽  
Defects In Semiconductors

The ability to correlate near-atomic resolution TEM images of defects with their cathodoluminescence (CL) spectra holds promise as a powerful technique for the study of the electronic structure of defects in semiconductors. We have constructed a CL detection instrument fitted to a Philips 400T electron microscope, similar to that described by Roberts, as shown in Fig. 1. The instrument uses an ellipsoidal mirror for light collection allowing operation in the TEM, STEM and REM modes in a relatively clean vacuum, and is compatible with the ELS and EDS modes. The ellipsoidal mirror was designed to collect the maximum amount of emitted light within the limitations of the spacing between the specimen holder and the upper pole piece of the twin lens, as shown in Fig. 2 and 3. The length of the major axis is 61.2 mm and that of the minor axis is 12.1 mm.

Electron-beam damage and analysis at low temperature

1990 ◽  
Vol 48 (4) ◽  
pp. 806-807
Author(s):  
Yoshio Bando ◽  
Yoshizo Kitami ◽  
Masato Yokoyama
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Low Temperature ◽  
Mass Loss ◽  
Radiation Damage ◽  
Liquid Helium ◽  
Inorganic Materials ◽  
Specimen Holder ◽  
Analytical System ◽  
Beam Damage

Elemental analysis for beam-sensitive materials is limited by radiation damage due to inelastic scattering of electrons. The amorphization and the mass loss often occure during the observation under a focused electron beam. It has been so far understood that the electron beam damage is effectively reduced by decreasing the specimen temperature. The cryo-electron microscope using liquid helium colled specimen holder is useful to minimize the radiation damage of the beam-sentitive materials. In the present paper, we have studied the radiation damage of various insulating inorganic materials in terms of the rate of the amorphization and the selective mass loss, which are observed at a room temperature (300K) and a low temperature (20K). All measurements are performed on a JEM-4000FX high-resolution analytical electron microscope with full analytical system. The specimen fragments placed on a holey carbon supporting grid are cooled down to about 20K. using a liquid helium specimen holder attached with a Be retainer.

High-Vacuum Evaporation and a Cryostage to Observe Fractured Yeast

1988 ◽  
Vol 46 ◽  
pp. 256-257
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Eugene L. Vigil
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Standard Specimen ◽  
High Vacuum ◽  
Specimen Holder ◽  
Sputter Coating ◽  
Fresh Frozen ◽  
Gain Access ◽  
Scanning Electron ◽  
Transfer Device

Investigators have long realized the potential advantages of using a low temperature (LT) stage to examine fresh, frozen specimens in a scanning electron microscope (SEM). However, long working distances (W.D.), thick sputter coatings and surface contamination have prevented LTSEM from achieving results comparable to those from TEM freeze etch. To improve results, we recently modified techniques that involve a Hitachi S570 SEM, an Emscope SP2000 Sputter Cryo System and a Denton freeze etch unit. Because investigators have frequently utilized the fractured E face of the plasmalemma of yeast, this tissue was selected as a standard for comparison in the present study.In place of a standard specimen holder, a modified rivet was used to achieve a shorter W.D. (1 to -2 mm) and to gain access to the upper detector. However, the additional height afforded by the rivet, precluded use of the standard shroud on the Emscope specimen transfer device. Consequently, the sample became heavily contaminated (Fig. 1). A removable shroud was devised and used to reduce contamination (Fig. 2), but the specimen lacked clean fractured edges. This result suggested that low vacuum sputter coating was also limiting resolution.

Development of a Philips cryo-TEM provided with a liquid helium cooled tilt stage and a vacuum transfer system

1998 ◽  
Vol 4 (S2) ◽  
pp. 400-401
Author(s):  
R. Wagner ◽  
A.F. de Jong ◽  
A.G. Koster ◽  
R. Morrison ◽  
F. Tothill ◽  
...  
Keyword(s):  
High Resolution ◽  
Liquid Helium ◽  
Signal To Noise Ratio ◽  
Transfer System ◽  
Helium Temperature ◽  
Single Particles ◽  
Signal To Noise ◽  
Specimen Holder ◽  
2D Crystals ◽  
Beam Damage

In order to reduce beam damage, biological TEM specimens are often observed at temperatures close to the boiling point of liquid nitrogen (77 K). Recently, encouraging results on single particles as well as on 2D crystals have appeared, derived from images taken near liquid helium temperature (4 K), in dedicated TEMs. At these temperatures the high resolution frequencies are much better preserved, increasing the allowable dose and thus the signal to noise ratio.4 Here we present the design of a new dedicated Philips He-TEM which combines the full functionality of a CM300 TWIN with a vacuum transfer system and a liquid helium cooled specimen holder.A schematic overview of the Cryo-TEM is shown in figure 1. The key differences compared to a standard CM microscope are: 1) The tip of the specimen rod is cooled below 10 K and the rod itself cannot be taken out of the goniometer (CompuStage). 2) The specimen enters the column on the opposite side.

scholarly journals Time-resolved studies of low-temperature, EUV-induced plasmas: EUV emission in selected spectral ranges

2019 ◽  
Vol 37 (4) ◽  
pp. 400-407 ◽  
Author(s):  
A. Bartnik ◽  
H. Fiedorowicz ◽  
P. Wachulak ◽  
T. Fok
Keyword(s):  
Low Temperature ◽  
Excited States ◽  
Extreme Ultraviolet ◽  
Detection System ◽  
Time Duration ◽  
Time Resolved ◽  
Euv Emission ◽  
Decay Times ◽  
Driving Pulse ◽  
Spectral Ranges

AbstractInteraction of extreme ultraviolet (EUV) pulses of high intensity with gases results in the creation of non-thermalized plasmas. Energies of the driving photons and photoelectrons are sufficient for creation of excited states, followed by emission of the EUV photons. In most cases, decay times of these states are short comparing to the driving EUV pulse. It means that just after stopping of the driving pulse, the EUV emission corresponding to the excited states should also stop. From our earlier measurements in the optical range, however, it can be concluded that lifetimes of such plasmas exceed a time duration of the driving pulse even two orders of magnitude. Hence, it can be expected that the time duration of the EUV emission can be also significantly longer than the irradiation time. In this work, EUV-induced, low-temperature helium (He), krypton, and xenon plasmas were investigated. EUV emission from these plasmas was studied, using a specially prepared detection system, allowing for time-resolved measurements, in selected spectral ranges. The detection system was based on a paraboloidal collector and a semiconductor photodiode, sensitive for the EUV photons. For spectral selection, the corresponding filters or multilayer mirrors were employed. In most cases, the time duration of the EUV emission was significantly longer than the driving EUV pulse. In case of He plasmas, the emission corresponding to excited atoms was detected even hundreds of nanoseconds after the irradiation. It was also shown that the corresponding time profiles depended on densities of gases to be ionized.

Room Temperature Sample Scanning SQUID Microscope for Imaging the Magnetic Fields of Geological Specimens

2013 ◽  
Vol 475-476 ◽  
pp. 3-6 ◽  
Author(s):  
Qing Meng Wang ◽  
Hua Feng Qin ◽  
Qing Song Liu ◽  
Tao Song
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Liquid Helium ◽  
Quantum Interference ◽  
Three Dimensional ◽  
Input Circuit ◽  
Pickup Coil ◽  
Weak Magnetic Fields ◽  
Scanning Squid

A microscope to image weak magnetic fields using a low-temperature superconducting quantum interference device (SQUID) had developed with a liquid helium consumption rate of ~0.5L/hour. The gradient pickup coil is made by a low-temperature superconducting niobium wire with a diameter of 66 μm, which is coupled to the input circuit of the SQUID and is then enwound on the sapphire bobbin. Both of the pickup coil and the SQUID sensor are installed in a red copper cold finger, which is thermally anchored to the liquid helium evaporation platform in the vacuum space of the cryostat. To reduce the distance between the pickup coil and sample, a 100 μm thick sapphire window is nestled up to the bottom of the cryostat. A three-dimensional scanning stage platform with a 50 cm Teflon sample rack under the sapphire window had the precision of 10 μm. To test the fidelity of the new facility, the distribution of the magnetic field of basalt slice specimens was determined. Results show that the spatial resolution of the newly-designed facility is 500 μm with a gradient magnetic field sensitivity of 380fT. This opens new opportunities in examining the distribution of magnetic assemblages in samples, which bear great geological and geophysical information.

Atomistic Visualization of Mechanical Interaction in Gold Crystalline Boundaries by Time-Resolved High Resolution Transmission Electron Microscopy

1998 ◽  
Vol 05 (03n04) ◽  
pp. 739-745
Author(s):  
Tokushi Kizuka
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Atomic Layer ◽  
Mechanical Tests ◽  
Atomic Scale ◽  
Mechanical Interaction ◽  
Time Resolved ◽  
Specimen Holder ◽  
Transmission Electron

The atomic processes in mechanical interaction were visualized by time-resolved high resolution transmission electron microscopy at a spatial resolution of 0.2 nm and a time resolution of 1/60 s. Nanometer-sized tips of gold were approached, contacted, bonded, deformed and fractured inside a 200 kV electron microscope using a piezo-driving specimen holder. The crystallographic boundary formed after the contact. A few layers near the surfaces and bonding boundaries were responsible for the approach, contact and bonding processes. Atomic scale mechanical tests, such as the friction test, compressing, tensile and shear deformation tests, were proposed. A new type of mechanical processing at one-atomic-layer resolution was demonstrated. Atomic scale contact or noncontact type surface scanning similar to that in atomic force microscopy was also performed with the gold tips.

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