Magnetic structures of NaFePO4 maricite and triphylite polymorphs for sodium-ion batteries.

The magnetic structure and properties of polycrystalline NaFePO4 polymorphs, maricite and triphylite, both derived from the olivine structure type, have been investigated using magnetic susceptibility, heat capacity, and low-temperature neutron powder diffraction. These NaFePO4 polymorphs assume orthorhombic frameworks (space group No. 62, Pnma), built from FeO6 octahedral and PO4 tetrahedral units having corner-sharing and edge-sharing arrangements.

Magnetic structure and properties of the Na2CoP2O7 pyrophosphate cathode for sodium-ion batteries: a supersuperexchange-driven non-collinear antiferromagnet.

The crystal and magnetic structure and properties of the Na(2)CoP(2)O(7) Na(+)-ion battery cathode material have been characterized by magnetic susceptibility, specific heat, and variable-temperature neutron powder diffraction measurements. Na(2)CoP(2)O(7) crystallizes in the orthorhombic space group Pna2(1) with a = 15.4061(3) Å, b = 10.