Abstract
Interest in Fe(ND 3) 2PO 4, one of the first three-dimensional structurally linked solids forming Fe–ND 3 bonds, has been renewed recently due to the observation of structural and magnetic phase transitions. This paper reports powder neutron diffraction experiments which show that Fe(ND 3) 2PO 4 crystallizes at room temperature in an orthorhombic ( Pnma) crystal structure, but that below T t = 226(5) K the crystal progressively adopts a monoclinic ( P2 1 /n) structure via a continuous phase transition, as observed from heat capacity measurements in the temperature range 250–100 K. In addition, neutron diffraction experiments suggest that the magnetic structure is non-collinear with an incommensurate propagation vector k → inc = ( 1 / 2 - τ , 0 , τ ) , with τ ∼ 0.04 reciprocal lattice units (rlus), and that the magnitude of the Fe(III) magnetic moments is close to μ Fe = 4.5 μ B at T = 2 K, describing a helimagnetic arrangement. To the best of our knowledge, this is an unprecedented magnetic ordering in an iron phosphate lattice. We argue that the proposed magnetic ordering can be explained by means of a model of superexchange interactions involving Fe–O–P–O–Fe paths.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
