Low temperature magnetic ordering in the frustrated zigzag ladder system BaNd$_{2}$O$_{4}$

The AR$_{2}$O$_{4}$ family (R $=$ rare earth) have recently been attracting interest as a new series of frustrated magnets, with the magnetic R atoms forming zigzag chains running along the c-axis. We have investigated polycrystalline BaNd$_{2}$O$_{4}$ with a combination of low temperature magnetization, heat capacity, and neutron diffraction measurements. This material has a Curie-Weiss temperature of -24 K, while our zero field heat capacity measurements indicate a magnetic transition of only 1.7 K, indicative of a high magnetic frustration index. Combined magnetization and neutron diffraction data show evidence for a complex, canted antiferromagnetic ground state with a propagation vector of (0 0.5 0.5) and the spins lying in the ac-plane. Furthermore, low temperature magnetization and heat capacity measurements as a function of applied field reveal that the order can be completely suppressed in an applied field of only 3.5 T. Direct comparison of these results to previous work on SrR$_{2}$O$_{4}$ shows that there is a rich diversity of magnetic behavior in this family of frustrated magnets, likely due to a competition between single ion anisotropy, dipole-dipole interactions, and exchange interactions.