¢º Instruments & Facilities
cryostats (3 sets)
Home-made standard liquid-helium-pumping-type cryostats. Each one consists of
vacuum-shielded nitrogen (outer) and helium (inner) glass dewars. Two of them
are equipped with double mu-metal shields. The optimum operation temperature
ranges from 1.2 K to 10 K, but operation up to 100 K is possible. One of them
can be used with a 7 T superconducting magnet.
(Oxford Instruments; Model AST Minisorb)
¡¤ Base temperature: continuous: ¡Â20 mK
¡¤ Expected pump switching time of 20-30 minutes
¡¤ Cooling power: ¡Ã40 ¥ìW
at 100 mK
¡¤ Sample space 37 mm diameter ¥¹ 78 mm
Dilution fridge (Oxford Instruments;
The system is designed and engineered to make millikelvin temperatures
accessible at a low cost to a wider range of researchers. Currently it is
equipped with 11 T superconducting magnet. The specifications are as follows.
¡¤ Base temperature: 50 mK
¡¤ Continuous flow operation
¡¤ Cooling power: 20 microwatts at 100 mK
¡¤ Cool down time from room temperature: less than 6 hours
General-purpose thermal evaporator
¡¤ mask aligner (home-made)
¡¤ photoresist spinner
¡¤ class 100 ovens (2 sets)
¡¤ optical microscope (Nikon; Model Optiphoto 66)
¡¤ photo-stage for producing optical masks
¡¤ Raith Model ELPHY QUANTUM beam control
¡¤ SEM (JEOL Model 5400).
deposition and etching system
¡¤ high vacuum system: base pressure; 1x10-7 Torr
¡¤ ion gun: (Anatech, 5 cm).
This system is designed to be used for fabricating ultra-pure thin films and,
if necessary, cleaning an interface between two successive depositions of
thin films using an ion gun. It consists of
¡¤ ultra-high vacuum system: base
pressure 1x10-9 Torr
¡¤ effusion cells (2 sets)
¡¤ ion gun.
(Koch Process Systems, Inc.; Model 1410)
¡¤ Cold box containing heat exchangers,
variable speed reciprocating expansion engines, liquid nitrogen precooling
system, automatic purification system, Joule-Thomson valve, delivery tube
gland and return valve assembly.
¡¤ One helium compressor (Model 1400)
¡¤ One 500 liter capacity liquid helium liquefaction dewar.
¡¤ One helium recovery compressor (Model 50B)
¡¤ One 300 SCF gas recovery bag.
The liquefaction rate is 12 liters/hour
with liquid nitrogen precooling.