Automatized magnetic transportation measuring system using phase lock amplifying technology

A technology of lock-in amplification and measurement system is applied in the field of automatic magnetic transport measurement system using lock-in amplification technology, which can solve the problem of low precision and achieve the effect of reducing large current.
CN101369010AActive Publication Date: 2009-02-18SHANGHAI INST OF TECHNICAL PHYSICS - CHINESE ACAD OF SCI
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Patent Information

Authority / Receiving Office
CN Β· China
Current Assignee / Owner
SHANGHAI INST OF TECHNICAL PHYSICS - CHINESE ACAD OF SCI
Publication Date
2009-02-18

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Abstract

The invention designs an automatic magneto-transport measurement system by using the phase lock amplification technology, which is used to accurately measure the characters related to electric transport of the material in low temperature and high magnetic field, such as measuring magnetoresistance shock, Hall Effect and the like. The system mainly comprises a standard Hall plate sample, a cooled cryostat and temperature control device, a magnet and magnet control device, two phase lock amplifiers, a current supply, a reverse cut-off circuit, a voltage supply, a GPIB control card and a computer. The measurement material is made into standard Hall plate sample, the computer is connected with each instrument through the GPIB bus, program is used to control each instrument to perform the automatic measurement, display the measurement results in real time, and store the measurement results as a data file. The system has the advantages that: 1. compared with the DC magneto-transport measurement, the system can use tittle measurement current to perform the magneto-transport measurement, and reduces adverse effects caused by big current and improves precision of the measurement; 2. the system can automatically change the grid voltage and magnetic field, and the (grid voltage)-(magnetic field) phase map can be given within one measurement.
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Description

technical field

[0001] The invention relates to a technology for measuring the electrical transport properties of materials under low temperature and strong magnetic fields, specifically an automatic magnetic transport measurement system using lock-in amplification technology, which is mainly suitable for the electrical transport of semiconductor materials under deep low temperature and strong magnetic fields Precise measurement of quantum effects. Background technique

[0002] In the physical research process of semiconductor materials and devices, magnetic transport measurement has always been an important and direct research method. Under different temperature and magnetic field conditions, the electrical transport properties undergo two processes, classical and quantum. By changing the external conditions such as temperature and magnetic field, not only the basic physical quantities such as carrier concentration and mobility in the sample can be obtained, but also some ...

Claims

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