An optical fiber Bragg grating (FBG) method developed at the HLD is used to measure magnetostriction in pulsed magnetic fields. The relative length change ΔL/L can be obtained from the shift of the wavelength of the reflected light in the FBG [1].

 Magnetostriction structure of an optical fiber Bragg grating  Magnetostriction principle of measurement
The structure of an optical fiber Bragg grating.
The principle of the measurement.

Relative length change (magnetostriction) thus is proportional to the relative wavelength change: Δλ/λ ∝ ΔL/L

Resolutions of about ΔL/L ~ 10-7 are achievable.

Standard temperature range is 1.4 – 300 K. Measurements down to ~0.6 K with a 3He system are also possible. This technique can be used in all our magnets.

The sample size should be > 1 mm.

Magnetostriction of single-crystalline LaCoO3   Magnetostriction of single-crystalline LaCoO3 (2)
Magnetostriction of single-crystalline LaCoO3 measured in pulsed magnetic fields. [2]


[1] R. Daou et al., Rev.Sci Instum. 81, 033909 (2010)

[2] M. Rotter et al., Sci. Rep. 4, 7003 (2014)