Principle

Giant magnetoresistance effect refers to the phenomenon that the resistivity of a magnetic material changes greatly when there is an   external magnetic field compared to when there is no external magnetic field. Giant magnetoresistance is a quantum mechanical effect, which results from the layered magnetic thin film structure. This structure is formed by alternately laminating thin layers of ferromagnetic material and non-ferromagnetic material. When the magnetic moments of the ferromagnetic layer are parallel to each other, the scattering of carriers and spins is the smallest, and the material has the smallest resistance. When the magnetic moment of the ferromagnetic layer is antiparallel, the spin-related scattering is the strongest and the material's resistance is the largest.

Overview

The main contents of this experiment include the measurement and exploration of the magnetoelectric conversion characteristics of the   giant magnetoresistive GMR analog sensor, the GMR magnetoresistive characteristics, and the magnetoelectric conversion characteristics of the GMR switch (digital) sensor, and the investigation of the current measurement using the GMR analog sensor. The exploration and   application of the characteristics of GMR gradient sensors, as well as the principle and process of learning magnetic recording and magnetic reading.

Features

• Independent experiment modules:

  A, giant magnetoresistive GMR basic characteristic measurement module;   B, giant magnetoresistive GMR measurement current module;   C, giant magnetoresistive GMR gradient sensor measuring gear angular displacement module;   D, giant magnetoresistive GMR magnetic card reading and writing Module.

• Rich experimental content:

  (1) Measure the magnetoelectric conversion characteristic curve of GMR analog sensor.

  (2) Measure the magnetic resistance characteristic curve of GMR.

  (3) Measure the magnetoelectric conversion characteristic curve of GMR switch (digital) sensor.

  (4) Measure the magnetic field distribution curve of the energized solenoid.

  (5) Measure the wire current with GMR sensor.

  (6) Use the GMR gradient sensor to measure the angular displacement of the gear to understand the principle of the GMR speed (speed) sensor.

  (7) The principle of magnetic card recording and reading through GMR sensor.

  
  

• Convenient data acquisition interface: The experiment power supply is equipped with 4 analog data acquisition interfaces, which can be connected to the voltage sensor and PASCO data acquisition software, and can collect a large amount of data in real time to   analyze the test results, which is convenient, fast and efficient to complete the experiment content.

Experimental content and typical data

Experiment 1: Measurement of magnetoelectric conversion characteristics of GMR analog sensor

Experiment 2: Measurement of GMR magnetoresistive characteristics

Experiment 3: GMR analog sensor measures current

Parts List

Adjustable DC (constant voltage and constant current) power supply I, 12V/1A BEM-5055

DC voltage and current meter I, 2V/20mA BEM-5056

Giant magnetoresistive basic characteristic measurement module BEM-5717

Giant magnetic resistance measuring current module BEM-5718

Giant magnetoresistive angular displacement measurement module BEM-5719

Giant magnetoresistive magnetic card reader module BEM-5720

Connecting wire, banana plug, 0.8 m, red BC-105084 [4]

Connecting wire, banana plug, 0.8 m, black BC-105083 [4]

Connecting wire, mini eight-pin wire BC-105243

Power cord BC-105075 【2】

User Manual CD-M-BEX-8511B

Digital experiment options

UI-5400    Capstone data acquisition software

PS-3211    Wireless voltage sensor　【2】