The resistance change of a material induced by a magnetic field is called the magnetoresistive effect, which includes normal magnetoresistance (OMR), anisotropic magnetoresistance (AMR), giant magnetoresistance effect (GMR), colossal magnetoresistance (CMR), tunneling magnetoresistance (TMR), and so on.
This instrument provides three kinds of magneto-resistance sensors, a multilayer membrane GMR sensor, a spin valve GMR sensor, and an anisotropic magneto-resistance sensor. It helps students understand the principles and applications of different magneto-resistance effects, and is suitable for fundamental physics experiments as well as modern physics experiments at universities.
Using this apparatus, the following experiments can be accomplished:
1. Understand magneto-resistance effects and measure the magnetic resistance Rb of three different materials.
2. Plot diagram of Rb/R0 with B and find the max value of resistance relative change (Rb-R0)/R0.
3. Learn to calibrate magneto-resistance sensor & calculate the sensitivity of three magneto-resistance sensors.
4. Measure the output voltage and the current of three magneto-resistance sensors.
5. Plot the magnetic hysteresis loop of a spin-valve GMR.
Main Parts and Specifications
|Multilayer GMR sensor||linear range: 0.15 ~ 1.05 mT; sensitivity: 30.0 ~ 42.0 mV/V/mT|
|Spin valve GMR sensor||linear range: -0.81 ~ 0.87 mT; sensitivity: 13.0 ~ 16.0 mV/V/mT|
|Anisotropic magnetoresistance sensor||linear range: -0.6 ~ 0.6 mT; sensitivity: 8.0 ~ 12.0 mV/V/mT|
|Helmholtz coil||number of turns: 200 per coil; radius: 100 mm|
|Helmholtz coil constant current source||0 - 1.2 A adjustable|
|Measurement constant current source||0 - 5 A adjustable|
Relationship between V and B of spin valve GMR sensor
Relationship between V and B of multilayer GMR sensor
Relationship between V and B of AMR sensor