The magnetostriction experimental station is a platform that uses magnetostrictive measurement technology to study how the dimensions of samples change with the magnetic field under strong magnetic fields. It employs the Fiber Bragg Gratings method, that the experimental sample is fixed at the bottom end of the measuring probe and is closely bonded with the Bragg grating. The Bragg grating is connected to the external optical path through an optical fiber. A broadband light source generated by a superluminescent diode-based broadband source enters the fiber Bragg grating via an optical circulator. Due to the grating having a certain spacing, light with a wavelength longer than this spacing will pass through, while light with a wavelength matching the spacing will be reflected back to the circulator and then demodulated by a spectrometer. When the sample undergoes a phase transition under a strong magnetic field, its volume and length change, thereby affecting the spacing of the grating. The movement of the grating spacing will be demodulated by the spectrometer, showing a distinct peak in the spectrum. By analyzing the wavelength at the peak of the reflection spectrum, the magnetostriction of the sample as a function of the magnetic field can be obtained.

Fig.1  The profile of the magnetostriction measurement system based on the Fiber Bragg Grating method.

Fig.2 The illustration of the sample connection based on the FBG method for the magnetostriction measurements.

Magnetostriction is produced by the coupling of the spins and orbits of atoms or ions in a material, and it is an external manifestation of the spin-orbit coupling energy and the material's elastic energy. It is generally believed that the magnetostriction phenomenon occurs with the spontaneous magnetization of ferromagnetic or ferrimagnetic materials below the Curie point. During the spontaneous magnetization process, a large number of magnetic domains are formed in the sample. The exchange interaction of atomic magnetic moments causes changes in atomic spacing, leading to lattice deformation. Figure 3 shows the magnetostriction effect of the honeycomb antiferromagnetic material Co₄Nb₂O₉ under pulsed magnetic fields.

Fig.3 the magnetostriction effect of the honeycomb antiferromagnetic material Co₄Nb₂O₉.

Measurement Conditions

Magnetic field:0-60 T

Resolution of ∆L/L:<10^-5

Measurement Temperature:1.5-250 K

Sample Type:Single crystal

Sample Size:< 4 mm*4mm

Reference

1. Xiao-Dong Zhang et al., Single‐Ion Magnetostriction in Gd₂O₃ –CeO₂ Solid Solutions.

Adv. Funct. Materials 32, 2110509 (2022).

2. Yuting Chang et al., Linear magnetoelectric memory and training effect in the honeycomb antiferromagnet. Phys. Rev. B 107, 014412 (2023).

3. Z. H. Li et al., Dimerization-enhanced exotic magnetization plateau and magnetoelectric phase diagrams in skew-chain Co₂V₂O₇. Phys. Rev. B 109, 094432 (2024).

Key Contact

Ming Yang

Email：ming_yang#hust.edu.cn  (Please replace # with @)