V vs B of spin valve GMR sensor
(Click graph to enlarge)
V vs B of multilayer GMR sensor
(Click graph to enlarge)
V vs B of AMR sensor
(Click graph to enlarge)
Features
Compact design
Ample experimental examples
Ideal for solid-state physics teaching
Introduction
The LEAI-75 Apparatus is designed to help students explore the magnetoresistive effects—the change in a material’s resistance in response to an applied magnetic field. These effects include normal magnetoresistance (OMR), anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), and others such as colossal magnetoresistance (CMR) and tunneling magnetoresistance (TMR).
Magnetoresistance is widely used in fields like magnetic storage, spintronics, and sensor technologies. The LEAI-75 system provides three types of magnetoresistance sensors: a multilayer membrane GMR sensor, a spin-valve GMR sensor, and an anisotropic magnetoresistance sensor. It is ideal for conducting material physics experiments and is particularly useful for modern physics courses at colleges and universities.
The instruction manual contains comprehensive materials including experimental configurations, principles and step-by-step instructions. Please click Experiment Theory and Contents to find more information about this apparatus.
Using this apparatus, the following experiments can be accomplished:
1. Understand Magnetoresistance Effects:
Measure and analyze the magnetic resistance (Rb) of three different materials (using the three sensors). This helps students understand the varying responses of materials to magnetic fields.
2. Plot the Resistance Change (Rb/R0 vs. B):
Students will plot the ratio of resistance change (Rb-R0)/R0 with respect to the magnetic field (B) and identify the maximum resistance relative change. This experiment helps in quantifying the sensitivity and efficiency of the materials.
3. Calibrate Magnetoresistance Sensors:
Students will learn how to calibrate magnetoresistance sensors and calculate their sensitivity. This is essential for understanding how these sensors can be used in practical applications like magnetic field sensing and current detection.
4. Measure the Sensor Output Voltage:
The apparatus allows students to acquire the relationship between the sensor output voltage and input current in a current-carrying wire, thereby calibrating a GMR current sensor.
5. Plot Magnetic Hysteresis Loop:
Using the spin-valve GMR sensor, students will be able to plot the magnetic hysteresis loop, which is an important tool in studying the magnetic properties of materials and is critical for applications in data storage and magnetic sensors.
Main Parts and Specifications
| Description | Specifications |
| Multilayer GMR sensor | linear range: 0.15 ~ 1.05 mT; sensitivity: 30.0 ~ 42.0 mV/V/mT MR resistance: 5.0 kΩ ± 1.0 kΩ, precise resistor: 1.20 kΩ |
| Spin valve GMR sensor | linear range: -0.81 ~ 0.87 mT; sensitivity: 13.0 ~ 16.0 mV/V/mT MR resistance: 1.3 kΩ ± 0.26 kΩ, precise resistor: 360 kΩ |
| Anisotropic magnetoresistance sensor | linear range: -0.6 ~ 0.6 mT; sensitivity: 8.0 ~ 12.0 mV/V/mT MR resistance: 1.0 kΩ ± 0.2 kΩ, precise resistor: 270 kΩ |
| Sensor power source | 5 VDC |
| 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 |
V vs B of spin valve GMR sensor
(Click graph to enlarge)
V vs B of multilayer GMR sensor
(Click graph to enlarge)
V vs B of AMR sensor
(Click graph to enlarge)
