We have performed resonant and non-resonant X-ray scattering on GdB6 to investigate the two successive phase transitions at TN=∼15K and T*=∼10K. Below TN, new superlattice reflection at the wave vector , which is the same wave vector determined by the epithermal neutron diffraction, has been observed by X-ray scattering. In the temperature region between T* and TN, it was confirmed by the polarization analyses that the superlattice reflection is due to magnetic X-ray scattering. On the other hand, interestingly, the superlattice reflection below T* is mainly due to Thomson scattering. Unlike behavior expected from usual magnetoelastic effects, the wave vector of the lattice distortion is identical to that of the magnetic structure below T*.
- Lattice distortion
- Magnetic X-ray scattering