Variable low speed Diamond saw : 
Materials (ceramics and metals) can be reduced to 0.5mm in thickness using this technique, which uses a diamond blade, with the wheel speed varying between 100 to 400 rpm.

Tuned Piezo Cutting Tool : 
This is used for cutting the material (both ceramic and metal) in the desired size and shape, so that it can be placed inside the TEM sample holder.

Ratings and Specifications : 

• Disc Cutter External PSU (Power Supply Unit)
  • Input Voltage = 100- 240 VAC (~)
  • Output Voltage = 24VDC
  • Output Power = 30W
  • Frequency = 47-63 Hz
  • Mains supply voltage fluctuations are not to exceed 10% of the nominal supply voltage
     
• Disc Cutter Power Jack ("DC in")
  • DC Input Voltage = 24 VDC
  • DC Input Current = 1.25 A
     
• Stereo Microscope Power Jack ("DC Out") used to power optional microscope
  • Output Voltage = 24 VDC
  • Output Current = 0.4A
     
• Environmental Conditions
  • Non-operating relative humidity (non- condensing): 10-90%
  • Storage temperature range 0- 65^oC
  • Operating Humidity Range: 20-80%
  • Operating maximum thermal gradient: 15^oC/hr
  • Operating temperature range: 16-24^oC
• (Information partly obtained from GATAN Manual)

Disc Punch : 
(Used only for metallic sheets) The Disc punch prepares specimen discs of 3 mm in diameter and material thicknesses ranging from 10 μm to above 100 µm.

Specimen mounting hot plate : 
This is used for firmly attaching specimen discs to stubs during grinding. This is done by using a low melting point wax polymer, heated on the hot plate, to form a strong, thin, hard adhesive bond. Operating temperature range is up to 130^oCC.

Disc grinder:
This is used for holding the stub with the specimen attached for grinding down to a certain thickness. The GATAN Model 623 Disc Grinder possesses superior resolution and preloading of the specimen drive screw to result in excellent control of specimen thickness. By using weight of the grinder it limit the maximum polishing pressure the operator is able to reduce specimen damage to a minimum. The samples are polished using different grit silicon carbide papers such as 40 µm,15 µm and 5 µm, in sequence.
(Information partly obtained from GATAN Manual)

Dimple grinder : 

After manual grinding, using disc grinder, precision thinning near the central region of the 3 mm disc specimen (or forming a dimple) is performed using dimple grinder.

The specifications are as follows:

• Environmental conditions
• Non –operating relative humidity: 10-90 %
• Storage temperature range: 0-65^oC
• Operating humidity range: 20-80%
• Operating maximum thermal gradient: 15^oC/hr
• Operating temperature range: 16-24^oC

Precision Ion Polishing System (PIPS) : 
After dimple grinding, the final stage precision polishing (thinning) of the 'dimpled' region up to electron transparency is done with the PIPS.
The specifications are as follows:

• Input Voltage = 100/120/240V
• Input Current = 3/3/1.5A
• Frequency = 50/60Hz
• Output Voltage = 120VAC 50/60Hz
• Output current = 3.0 A Max.
• Non-operating relative humidity (non - condensing): 10-90%
• Storage temperature range: 0- 65^oC
• Operating humidity range: 20-80%
• Operating maximum thermal gradient: 15^oC/hr
• Operating temperature range: 5-35^oC
• For indoor use only

(Information partly obtained from GATAN Manual)

The facility for preparation of TEM samples, following the more conventional route, consists of a number of equipments (see below) under one roof, which needs to be used in a proper sequence. Also, TEM sample preparation necessitates manual skills, which again varies from sample to sample, depending on the properties and type. Hence, unlike most other facilities, there is no particular way of 'operation', that would lead to best possible result. It solely depends on experience with handling different type(s) of samples and hence it is recommended that somebody aiming to make TEM samples regularly should get trained, rather than depending on the TAs/staff-in-charge. 
 

• Variable low speed Diamond saw is capable to cut the materials like ceramics, glasses and metals with high precision.
• Tuned Piezo Cutting Tool cuts the planner and cross-sectional samples with high precision without damaging it.
• Disc punch is capable to cut a specimen (only for metal sheets) discs of 3 mm in diameter and material thicknesses ranging from 10 μm to 100 μm.
• Disc grinder is an accurate and dependable tool for mechanically pre-thinning specimens with high quality and uniform thickness. The pre-thinning and polishing procedures reduce overall time and improve quality of the final specimen.
• Dimple grinder is used to dimple materials like ceramics and semiconductors below 3 μm with practically no mechanical damage and viewed subsequently in intermediate and high voltage TEMs without further thinning
• Precision Ion Polishing System (PIPS) is used as a final thinning or milling of the sample to provide electron transparent material for TEM analysis.

The quality of TEM images depends quite considerably on the sample preparation process, which involves thinning it down via cutting, grinding, dimpling and ion-milling to make the sample electron transparent. Care needs to be taken so that the sample preparation process does not affect properties of the material.

• Maximum two samples are allowed in one slot, which can be either forenoon or afternoon of any working day. Please note that the actual time taken for TEM sample preparation can extend beyond the duration of a slot.
• Dimensions of the sample should be sufficient enough for TEM sample preparation.
• The user must be available during the TEM sample preparation process throughout.

• Maximum two samples are allowed in one slot, which can be either forenoon or afternoon of any working day. Please note that the actual time taken for TEM sample preparation can extend beyond the duration of a slot.
• Dimensions of the sample should be sufficient enough for TEM sample preparation.
• The user must be available during the TEM sample preparation process throughout.