Observation of a transverse magnetization in the ordered phases of the pyrochlore magnet Gd2Ti2O7

We have performed a detailed transverse magnetization study of the pyrochlore antiferromagnet Gd 2 Ti 2 O 7 . A transverse magnetization of about 10 − 3 M sat is observed in the low-temperature ordered phases. These measurements result in the refinement of the Gd 2 Ti 2 O 7 phase diagrams. Observation of a transverse magnetization indicates loss of the cubic symmetry in some of the magnetic phases and provides new information for a better understanding of the complicated magnetic ordering of Gd 2 Ti 2 O 7 . Gadolinium compounds Gd 2 Ti 2 O 7 and Gd 2 Sn 2 O 7 provide good examples of the Heisenberg antiferromagnets on the pyrochlore lattice. The magnetic Gd 3+ ions are located at the vertices of the network of corner sharing tetrahedra. The nearest neighbor Heisenberg exchange interaction is strongly frustrated in this geometry — nearest neighbor exchange coupling alone is not sufficient to select a unique ground state of the pyrochlore antiferromagnet. However, both of these compounds orders near 1K [1]. This ordering is caused by the subtle interplay of weaker interactions (e.g. dipolar coupling, further neighbor exchange couplings and single-ion anisotropy).