Hall Measurement System
MMR’s Variable Temperature Hall System (VTHS) allows the user to make automatic measurements of resistivity, mobility and carrier concentration of a wide range of samples using the Van der Pauw method over a temperature range from 70K to 730K. Sample mounting is simple and allows rapid interchange of samples. The VTHS Hall Measurement Controller, the H5000, is compatible with a variety of computers through an USB or RS-232 interface. MMR’s Benchtop Electromagnet and Programmable Power Supplycomplement the VTHS. The system uses the VTHS Dewar described below.
Features
- Operating Temperature: 70 K to 730 K
- Guarded Triax Leads
- H5000 interfaces with MMR’s Low Temperature Dewar
- H5000 interfaces with MMR’s Programmable Temperature Controller
- H5000 interfaces with two different MMR electromagnets, allowing maximum flexibility in sample analysis.
- Hall magnetometer in Dewar included in system
- Full software provided for all measurements
- Power Input: 110 V, 60 Hz and 220 V, 50 Hz
- H5000 Weight: 12 lb
- H5000 Dimensions: 3.5″ x 8.5″ x 14″
Variable Temperature Hall Dewar
The VTHS Dewar is a low-profile Dewar designed to fit between the poles of a magnet to enable measurements to be made of the resistivity, Hall mobility and other properties of materials over a wide range of temperatures. Guarded triax leads provide electrical input to the sample via similarly guarded leads on a Kapton Harness to the sample on the cold stage. A Hall sensor immediately adjacent to the sample allows measurement of the magnetic field at the sample location.
In addition to the refrigerator and vacuum chamber, a temperature controller is needed, either manual or programmable; a source of dry nitrogen (99.998% purity); a filter dryer; and a vacuum pump capable of maintaining a vacuum <5 mTorr in the chamber. Other accessories that add to the convenience of operating the system are available from MMR.
Features
- Operating Temperature: 70 K to 730 K
- Temperature Stability: ± 0.1 K with MMR’s Programmable Controller
- Temperature Response: 1 K/sec
- Cooling Capacity: 250 mW at 85 K with nitrogen; 500 mW with Ar at 90 K
- Cold Pad Size: 14 mm x 10 mm
- Standard Window Material: Fused silica
- Optional Window Materials: Sapphire, Quartz.
- Guarded triax leads to sample
- Four sample leads for Van der Pauw measurements
- Extra BNC lead for heater for Seebeck measurements
- Simple sample mounting
- Integral Hall sensor at sample site
- Compatible with two different MMR electromagnets, allowing maximum flexibility in sample analysis
- Dewar Dimensions: 6.0″ L x 2.5″ W x 0.75″ H at sample
- Weight of Vacuum Chamber: 170 g (6 oz)