Complex magnetism of quasi-1D maricite-type NaFePO4

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AOCNS 2015
We recently reported the magnetic structure of maricite-type NaFePO4 determined using neutron powder diffraction data collected at 3 K1. The crystal structure of this compound is derived from the olivine (Mg2SiO4) type by an ordered distribution of Na and Fe over the two inequivalent Mg sites in the olivine cell. This leads to a magnetically quasi-1D arrangement in which edge-sharing (FeO6) chains are connected to each other only via phosphate groups with a shortest interchain Fe-Fe distance of ~5 Å vs. intrachain distance of ~3.4 Å. Here we report the results of further studies using magnetometry, heat capacity, Mossbauer, and variable field and temperature powder and single crystal neutron diffraction measurements, which reveal not only an intermediate incommensurate magnetic phase existing in zero field within a very narrow interval of ~2 K, but also a metamagnetic transition around 5 T (at 2 K). We will also present and discuss the evolution of the magnetic structure of NaFePO4 as a function of temperature and magnetic field in connection with the crystal structure and compared to that of other maricite type compositions such as AgMnVO42.
Crystal structure, Magnetic properties, Magnetometers, Neutron diffraction, Specific heat, Olivine
Avdeev, M., Piltz, R., Ling, C. D., Auckett, J., Barpanda, P., & Cadogan, S. (2015). Complex magnetism of quasi-1D maricite-type NaFePO4. Paper presented at 2nd Asia Oceania Conference on Neutron Scattering (AOCNS 2015), Novotel, Manly Pacific, Sydney, Australia, 19-23 July 2015.