Two-dimensional (2D) materials, such as transition metal disulfides and graphene, are of interest because of their interesting electronic and optical properties (e.g. metal-insulator transitions based on structural changes). The atomic arrangement of 2D materials is vital for understanding their characteristics. Transmission electron microscopy (TEM) is undoubtedly a versatile and powerful tool for characterizing the morphology, chemical composition, crystal structure and electronic structure of materials at atomic resolution.
Alfa Chemistry provides TEM testing to examine the crystal structure, grain boundaries, and flaws in 2D materials, all of which contribute to their macroscopic properties. Please contact us right away so that we can help you with your tests!
Why TEM
Transmission electron microscopy (TEM) is the most commonly used technique to obtain structural information. It is surely a potent instrument for static characterization and dynamic modification of nanomaterials and nanodevices at the atomic scale, thanks to its great spatial resolution and varied external field.
Fig 1. Overview of the in situ TEM characterization and manipulation of 2D layered materials in the various research areas and wide range of applications. (Luo C, et al. 2017)
The technique is capable of producing images with atomic resolution. Radiation, on the other hand, has a considerable impact on this capacity; beamless damage imaging is often only possible at low accelerating voltages below the chain damage threshold. The resolution-limiting aberrations can seriously disturb the imaging attempt at these low values. The employment of a cold-field emission gun or monochromatization of the electron beam has been proved to be a reliable way for eliminating color blur. At low accelerating voltages, probe correctors can improve the signal even more by lowering or even eliminating aberrations.
Rapid advances in thin-film and precision microelectromechanical systems (MEMS) technology have made it possible to probe and design 2D layered materials and nanodevices in the TEM in the presence of external stimuli such as thermal, electrical, mechanical, liquid/gas environments, optical, and magnetic fields. This advanced technology leverages traditional static TEM characterization into in-situ and interactive manipulation of 2D layered materials without sacrificing resolution or high vacuum chamber environments, helping to explore the intrinsic structure-property relationships of 2D layered materials.
Service Detail
| Testing Services | Transmission Electron Microscope (TEM) |
| Test Content | STEM, EELS, EDS, Mapping |
| Sample Type | Powder / Film / Bulk / Liquid |
| Instrument Model | FEI Tecnai F20 TEM, JEM-2100F Field Emission Electron Microscope, Talos F200X G2 TEM |
| Lead Time | 2~3 weeks |
Our requirements for samples are as follows:
- For liquid samples: ≥ 5 mL
- For powder samples: ≥ 5 mg
- Thin films and blocks cannot be tested directly and require some preparation such as ion thinning, double spraying, focused ion beam (FIB) and slicing. For these preparations, please contact us in advance to confirm.
Sample composition requirements:
(1) Safety: Non-toxic and non-radioactive.
(2) Organic: Mapping tests cannot be performed on samples containing organic material.
(3) Magnetism: Some materials are susceptible to magnetization when exposed to magnetic fields, and enhanced magnetism after heating is also defined as magnetic samples. Please confirm whether the sample is magnetic or not and inform us in time.
Note:
- Alfa Chemistry will test to the best of its ability, but cannot guarantee that the intended results will be reached. This is particularly true for magnetic samples or those with low electrical conductivity. Thanks for your consideration.
- SCALE is typically available up to 5 nm, however the photo quality is highly dependent on the sample conditions.
- All samples are non-refundable; if you have any special demands, please contact us.
Reference
- Luo C, et al. (2017). "In Situ Transmission Electron Microscopy Characterization and Manipulation of Two-Dimensional Layered Materials beyond Graphene." Small. 13(35): 1604259.
Please kindly note that our products are for research use only.
