Submitted:
24 July 2026
Posted:
24 July 2026
You are already at the latest version
Abstract
The phase-pure syntheses of Fe(dca)₂ and Fe(dca)₂(NH₃)₂ have enabled comprehensive investigation of their structural and magnetic properties. Fe(dca)₂ crystallizes in the orthorhombic space group Pnnm, with Fe²⁺ ions octahedrally coordinated by six dca ligands, forming a rutile-like 3D network. Temperature-dependent structural analysis reveals minor distortions and a slight unit cell volume contraction (~2.5 ų) from 300 K to 25 K. Fe(dca)₂(NH₃)₂ crystallizes in the monoclinic space group P2₁/c, featuring two axial ammonia ligands and dca-bridged Fe²⁺ ions forming layers. Magnetic susceptibility measurements of Fe(dca)₂ reveal a ferrimagnetic transition at TC = 19.1 K, con-firmed by SQUID data, Mößbauer spectroscopic measurements and low-temperature neutron diffraction. A magnetic hysteresis at 5 K indicates long-range cooperative magnetic ordering. ATR-IR spectroscopic measurements support the structural models and confirm the chemical composition of both compounds. TGA shows the thermal decomposition of Fe(dca)₂.
Keywords:
crystal structure
; iron
; dicyanamide
; ammonia
; magnetism
; X-ray diffraction
; neutron powder diffraction
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