Neutron Diffraction, Mössbauer Spectrum, and Magnetic Behavior of Ag2FeMn2(PO4)3 with Alluaudite-like Structure

✍ Scribed by N. Chouaibi; A. Daidouh; C. Pico; A. Santrich; M.L. Veiga

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 389 KB
• Volume: 159
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9128

✦ Synopsis

The new compound Ag 2 FeMn 2 (PO 4 ) 3 has been synthesized using solid state reactions, and characterized by X-ray and neutron di4raction. It crystallizes in the monoclinic space group C2/c with the parameters a ‫؍‬ 12.1466(3) A s , b ‫؍‬ 12.7328(4) A s , c ‫؍‬ 6.4999( 5) A s , and ‫؍‬ 114.53(3)3. Its structure is formed by [FeMn 2 O 12 ] chains of edge-sharing FeO 6 and MnO 6 octahedra. The chains are interconnected by the PO 4 tetrahedra giving rise to layers parallel to the ac plane and exhibiting a three-dimensional channel-like structure where the silver cations are located. The distribution of the FeO 6 and MnO 6 octahedra along the chains was determined by the neutron re5nements. The MoK ssbauer spectral parameters indicate the presence of only Fe(III) octahedral sites. The reciprocal susceptibility variation shows a deviation from the Curie+Weiss law below 19 K, which can be attributed to a weakly ferromagnetic component owing to probable canting of antiferromagnetically coupled spins along the [FeMn 2 O 12 ]

chains.