Variable Temperature Hall Measurement Systems
The variable temperature Hall Effect Measurement System is designed to provide totally automatic measurements of the electrical properties of semiconductor and high temperature semiconductor materials using the van der Pauw measurement technique.
When a current-carrying conductor is placed into a magnetic field, a voltage will be generated perpendicular to both the current and the field. This principle is known as the Hall effect.
The figure on the right illustrates the basic principle of the Hall effect. It shows a thin sheet of semiconducting material (Hall element) through which a current is passed. The output connections are perpendicular to the direction of current. When no magnetic field is present, current distribution is uniform and no potential difference is seen across the output. When a perpendicular magnetic field is present, a Lorentz force is exerted on the current. This force disturbs the current distribution, resulting in a potential difference (voltage) across the output. This voltage is the Hall voltage (VH).
The ratio of voltage created to product of the amount of current and the magnetic field divided by the element thickness is known as the Hall coefficient; this is characteristic of the material being measured. The Hall effect is a conduction phenomenon which is different for different charge carriers. In most common electrical applications, the conventional current is used partly because it makes no difference whether you consider positive or negative charge to be moving. But the Hall voltage has a different polarity for positive and negative charge carriers, and it has been used to study the details of conduction in semiconductors and other materials which show a combination of negative and positive charge carriers.
Features and Benefits
The variable temperature Hall and van der Pauw Measurement systems are noted for their unique benefits and features, making these systems easy to use and valuable additions to research facilities:
- Modular - you can build the systems up over time to meet your budget and experimental needs.
- Two Sizes of Systems Available:
- Bench-top Configuration: small and compact in size
- Large High Field Magnets: powerful measurement systems with the largest range of samples possible
- Excellent temperature setability, stability, and reproducibility.
- Absence of mechanical, acoustic, or electrical noise.
- Fast cool down and warm up times, with frost free operation.
- Wide range of operation: 70K to 730K
- Non-magnetic electrical feedthroughs facilitate electrical connections directly to samples on the thermal stage.
- Low cost of operation: $0.50/hour
- On the Joule-Thomson stages there are no liquid cryogens to handle.
- Very low power consumption - less than 12 watts on any stage.
- Seebeck Add-On Option Available to expand your measurement capabilies.
- Three Magnet Options Available - Low and High Field Systems
MMR Technologies Variable Temperature Hall Measurement system is one of the more valuable instruments for solid state characterization. There are many possible applications for these systems, including but not limited to:
- Hall effect devices:
- Immune to dust, dirt, mud, water
- Better for position sensing
- Hall sensors:
- Can easily detect stray magnetic fields
- Work well as electronic compasses
- Hall effect current transducers:
- High accuracy, environmentally hardy, low power consumption
- Ideal solution for solar energy management
- Electrical Measurements
- Material studies