Enhancement of spin relaxation in an FeDy2Fe coordination cluster by magnetic fields

Two [FeLn2Fe(µ3-OH)2(teg)2(N3)2(C6H5COO)4] compounds (where Ln=YIII and DyIII; teg=triethylene glycol anion) have been synthesized and studied using SQUID and Mössbauer spectroscopy. The magnetic measurements on both compounds indicate dominant antiferromagnetic interactions between the metal centers. Analysis of the 57Fe Mössbauer spectra complement the ac magnetic susceptibility measurements, which show how a static magnetic field can quench the slow relaxation of magnetization generated by the anisotropic DyIII ions.