Magnetostriction measuring device based on an optical fiber sensor with an annular photodiode

Area of Science:

• Materials Science
• Physics
• Instrumentation

Background:

• Magnetostriction is a critical property of magnetic materials, influencing their performance in various applications.
• Accurate measurement of magnetostriction is essential for material characterization and development.
• Existing methods for measuring magnetostriction can be complex or lack sensitivity.

Purpose of the Study:

• To develop a new, simple, and highly sensitive dilatometer for measuring magnetostriction in ribbon-shaped materials.
• To utilize an optical fiber sensor with an annular photodiode for enhanced measurement capabilities.
• To demonstrate the device's effectiveness with a specific amorphous ribbon sample.

Main Methods:

• A novel dilatometer design employing a bidirectional optical fiber sensor (emission and detection).
• Utilizing an annular photodiode for light detection.
• Measurement based on the reflection principle to determine the longitudinal displacement of the ribbon end.

Main Results:

• The developed dilatometer successfully measured magnetostriction in a Vitroperm amorphous ribbon (100 mm length, 21 µm thickness, 8.3 mm width).
• A longitudinal displacement of 2.571 µm was accurately recorded.
• The measurement achieved a maximum uncertainty of 8 nm, demonstrating high precision.

Conclusions:

• The new optical fiber dilatometer provides a simple and sensitive method for magnetostriction measurement.
• The bidirectional optical fiber design simplifies access and operation.
• The high precision achieved validates the sensor's potential for advanced materials characterization.