Measurement system for electrical transport propertiesA fully automated testing system that integrates Hall effect, magnetic resistance, I-V characteristics, and other tests. The system comprehensively considers issues that users often overlook, such as instrument configuration and circuit wiring (including room temperature and low temperature wiring), and selects Keithley's electrical measuring instruments from the United States. The magnetic field uses electromagnets or helium free superconducting magnets according to user needs, equipped with flexible measurement sample rods, and fully automated specialized testing software, which allows users to quickly and conveniently conduct sample testing and obtain accurate and reliable data.

Measurement system for electrical transport propertiesmain features:

1) The standard system uses plug-in sample fixtures, making sample installation convenient;

2) Basic configuration: Up to four samples can be added at once, and two samples can be tested simultaneously;

3) The standard system randomly distributes a probe sample card;

4) The standard system can measure the Hall effect and I-V characteristics under different magnetic fields;

5) Wide range of resistance measurement: 0.1m Ω -50G Ω (high resistance system), with a measurement uncertainty of 2%;

6) The testing and calculation processes are automatically executed by software, saving a lot of time;

7) The software can display measurement results and curves;

8) The system's magnetic field adopts closed-loop control, which can provide a highly stable magnetic field and solve the problem of residual magnetism in magnets, achieving true zero magnetic field;

9) By selecting variable temperature options, Hall effect measurements and I-V characteristic measurements can be conducted at different temperatures.

Basic configuration components:

1、 Measurement instrument section

Standard system: Keithley's 2400 ammeter, 27 multimeter, 7709 matrix card, interface adapter, and GPIB cable from the United States.

High impedance system: Keithley 6220 ammeter from the United States 2182A nanovoltmeter, 6485 picoampere meter, 6514 electrostatic meter, 7001 switch box, 7152 matrix card, and corresponding connecting cables, interface adapters, and GPIB cables.

2、 Components of magnetic field

Electromagnetic system:

Choose the electromagnet according to the size of the magnetic field required by the user (see the homepage for the electromagnet category), and then select the corresponding power supply for the electromagnet. If the magnetic field is above 3T, superconducting magnets and superconducting power supplies are required.

3、 Accessories section

Test assembly: including sample rod and bracket assembly, sample box module, sample card, and connecting test cable, etc;

Instrument installation cabinet, high-performance computer, and LCD display;

Special software for resistivity measurement system;

Installation and operation manuals, etc.

The electrical transmission testing system can test materials:

Semiconductor materials:

Thin films and bulk materials of Si, Ge, GaAs, GaN, AlGaAs, CdTe, HgCdTe, CdTe, ZnO, SiC, GeSi, InP, MCT, as well as weak magnetic semiconductors and dilute magnetic semiconductors;

Ferrite materials;

Low impedance material:Metals, transparent oxides, weak magnetic semiconductor materials, TMR materials, etc.

Basic functions of the electrical transmission testing system:

Can measure Hall effect, I-V characteristics (resistivity), and magnetoresistance (MR);

Parameters can be obtained: Hall effect - block resistance, resistivity, Hall coefficient, conductivity type, Hall mobility, carrier concentration;

The characteristic curve of I-V MR includes:

I-V characteristic curves under different magnetic fields

I-V characteristic curves at different temperatures

Temperature dependent I-V characteristic curves under different magnetic fields

I-V characteristic curves of variable magnetic field at different temperatures

Characteristic curve of resistance changing with temperature and magnetic field

P-B curve

Main technical indicators of the electric transmission testing system:

Sample size of electric transportation measurement system:

1) Small size double-sided sample card, with an area of 12 × 12mm2 (10 randomly distributed);

2) Large size single-sided sample card, with an area of 50 × 50mm2 (10 randomly distributed);

3) Probe sample card, capable of measuring sample size range: 1 × 1mm2, Approximately 30 × 30mm2 (1 randomly delivered).

Wiring method for samples of electrical transportation measurement system:

1) Hall effect measurement:

Van der Pauw；

Hall bar 1-2-2-1；

Hall bar 1-3-1-1；

Hall bar 1-3-3-1；

2) I-V characteristics and magnetoresistance measurement: inline four point method

Sample wiring method for electrical transportation measurement system:4-line or 6-line method

Temperature environment of electric transportation measurement system (standard system does not come with variable temperature option, can only measure at room temperature):

Liquid helium free superconducting magnet system (with built-in low-temperature options, no need to choose separately): 1.6K~325K

Options for liquid nitrogen thermostat in electric transportation measurement system:

Standard liquid nitrogen thermostat: 80K~325K

High temperature liquid nitrogen thermostat: 80K~500K

Circulating refrigeration machine option (does not consume refrigerants such as liquid helium/liquid nitrogen):

Standard 4K refrigeration system: 4K~325K

High temperature 4K refrigeration system: 4K~500K

High temperature 4K refrigeration system: 4K~700K

Standard 10K refrigeration system: 10K~325K

High temperature 10K refrigeration system: 10K~500K High Temperature 10K Refrigeration System: 10K~700K

Micro refrigeration system: 45K~325K