Magnetic structure of molecular magnet Fe[Fe(CN)6]·4H2O

Pramana

Amit Kumar¹  S M Yusuf1¹ 

[1] Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India$$

关键词: Molecular magnet;    neutron diffraction;    DC magnetization;    ferromagnet.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We have studied the magnetic structure of Fe[Fe(CN)6]·4H2O, prepared by precipitation method, using neutron diffraction technique. Temperature dependent DC magnetization study down to 4.2 K shows that the compound undergoes from a high temperature disordered (paramagnetic) to an ordered magnetic phase transition at 22.6 K. Rietveld analysis of neutron diffraction pattern at 60 K (in its paramagnetic phase) revealed a face centred cubic structure with space group Fm3m. The structure contains three-dimensional network of straight Fe3+ –C≡N–Fe3+ chains along the edges of the unit cell cube. Fe3+ ions occupy 4𝑎 (0, 0, 0) and 4𝑏 (1/2, 1/2, 1/2) positions. Fe3+ (0, 0, 0) is surrounded octahedrally by six nitrogen atoms and Fe3+ (1/2, 1/2, 1/2) is surrounded octahedrally by six carbon atoms. Magnetic Rietveld refinement of neutron diffraction data at 11 K shows a ferromagnetic coupling between the two inequivalent Fe3+ sites. Refinement yielded an ordered moment of 4.4(6) and 0.8(6) 𝜇Bper Fe ion located at (0, 0, 0) and (1/2, 1/2, 1/2), respectively. Ordered moments are found to align along the face diagonal. The observed net moment from low temperature neutron diffraction study is consistent with DC magnetization results.

【 授权许可】

Unknown