Resonant magnetic X-ray diffraction study on the triangular lattice antiferromagnet GdPdAl

Inami, Toshiya; Terada, Noriki*; Kitazawa, Hideaki*; Sakai, Osamu*

Resonant magnetic X-ray diffraction experiments were carried out on the stacked triangular lattice antiferromagnet GdPdAl. The experiments revealed an expected initial collinear -axis order at followed by an additional in-plane order at , while at the same time we found that the ground state is a helically ordered state of a very long incommensurate period of approximately 700 . The distribution of K-domains was highly anisotropic, and the domain with the modulation vector normal to the surface of the crystal was ascendant. Low-field magnetization is discussed on the basis of the observed incommensurate magnetic structure.