Nature of the Magnetic Order in the New Nd-based Pyrochlore Nd2Pt2O7

We propose to carry out neutron diffraction experiments on Nd2Pt2O7 using WISH. We have successfully synthesized a polycrystalline sample of this new member of the Nd-based pyrochlore family. Nd2Zr2O7 orders at 285 mK with an all-in-all-out (AIAO) anti-ferromagnetic (AFM) structure and exhibits magnetic fragmentation, while Nd2Sn2O7 adopts a noncoplanar AIAO structure below 0.91 K. For Nd2Pt2O7, our heat capacity and magnetization data reveal this system orders magnetically at a much higher temperature of 1.4 K. While an AIAO structure is anticipated, the exact nature of the magnetic order is unknown. Hysteresis in the magnetization vs temperature curves below the ordering T suggests a canting or FM component to the ordering. It is crucial to determine the magnetic structure of Nd2Pt2O7 in order to develop a unified understanding of the physics of the Nd-based pyrochlores.