CT1 Cryo-TEM Sample Storage Box & Transfer Rod

TEM Carbon Support Films & Quantifoil Holey Carbon Films

Ultrathin Carbon Film

Ultrathin carbon film is a type of support film consisting of a
very thin carbon layer deposited over a microgrid support film.
The carbon layer is generally 3–5 nm thick.

The ultrathin carbon layer covers the micropores and is mainly intended
for well-dispersed nanomaterials, especially samples below 10 nm.
When a microgrid is used alone, very small particles may fall through
the holes, while particles near the edges of the holes may be difficult
to observe because of the thicker support area.

Ultrathin carbon film is therefore suitable for obtaining improved
observation results. Available grid materials include copper,
nickel, molybdenum and gold.

Holey Carbon Support Film

Holey carbon film is a support film with micropores formed in the film,
and is therefore also referred to as a holey support film.
It is a carbon-coated support film with a typical film thickness
of 15–20 nm.

The main purpose is to position specimens at the edges of the support
holes so that areas of the specimen can be observed without an
underlying film. This helps improve image contrast.

Holey carbon support films are commonly used for tubular,
rod-shaped and nanoparticle specimens, and are particularly useful
for high-resolution imaging.

Carbon film thickness can be customized according to the application.
For particles smaller than 10 nm, ultrathin carbon film is recommended.

Carbon Support Film

Carbon support film is a specimen carrier used for transmission
electron microscopy (TEM). A carbon layer is deposited over an
organic Formvar film.

During TEM observation, the support film may accumulate electrical
charge under electron-beam irradiation, causing specimen charging,
drift, movement or support-film cracking.

Carbon coating improves the conductivity of the support film and
helps provide better observation results. This carbon-coated
grid support film is commonly referred to as a carbon support film.

Typical film thickness is 7–10 nm. The support film is mainly
composed of an organic layer with a relatively thin carbon coating,
so background interference is generally low.

Samples are commonly dispersed in water or ethanol, and the support
film is generally resistant to corrosion.

Double-Grid Carbon Support Film

Double-grid carbon support film is designed specifically for
magnetic specimens. Magnetic specimens may contaminate the
electron microscope, so carbon films are mounted on both grids
and the specimen is enclosed between them for protection.

The double-grid carbon support film is simple to use and is operated
similarly to a conventional single-grid carbon support film.
The dispersed specimen is placed on one grid and the second grid
is then attached over it.

This reduces the complicated conventional preparation procedure
for magnetic specimens and shortens specimen preparation time.
Magnetic powder samples can be prepared either by resin embedding
and ultrathin sectioning or by using a double-grid carbon support film.

Quantifoil Holey Carbon Film

Quantifoil is a perforated support film with precisely arranged holes
in different sizes and shapes. Compared with conventional holey carbon
films, this support film offers advantages for transmission electron
microscopy (TEM) grids and low-energy electron point-source microscopy
(LEEPS).

The fixed geometric arrangement of Quantifoil holes facilitates
automated operation in TEM, which is generally not possible with
conventional carbon films.

Quantifoil carbon support films have a large open-hole area and are
commonly used to reduce specimen thickness and minimize artifacts
caused by the support film.

The perforated film can support ultrathin films or can be used directly
as a carrier for larger specimens such as micron-scale powders.
This is important for electron diffraction (ED), electron energy-loss
spectroscopy (EELS), EELS imaging and dark-field imaging.

Quantifoil films can also be used for nanomaterial characterization,
including studies of biological macromolecular complexes suspended
freely over the holes.

Surface properties, especially wettability, may be adjusted according
to user requirements. Like other carbon films, untreated Quantifoil
films gradually lose hydrophilicity over time, while newly prepared
carbon films generally have better hydrophilicity.

Round-Hole Quantifoil Carbon Film

Round-hole Quantifoil carbon film is more suitable for cryogenic
transmission electron microscopy (Cryo-TEM), because circular holes
help form ice layers with more uniform thickness.

Hole spacing should be selected according to the required magnification
and whether the support-film pattern will appear in the final image.
When the film is included in the final image, image-quality evaluation
is easier because the film provides more acceptable isolated ice areas
than other hole shapes.