Magnetic and thermodynamic properties of Sr2LaFe3O9

Measurements of the magnetization, specific heat, and Fe-57 Mossbauer spectrum are presented for Sr2LaFe3O9. The temperature dependence of the specific heat and magnetization indicates that Sr2LaFe3O9 undergoes an antiferromagnetic transition at T-N=203 K. The small entropy removal Delta S and small effective paramagnetic moment mu(eff) suggest an itinerant character for the Fe moment in this compound. In low applied fields, the zero field cooled (ZFC) and field cooled (FC) magnetization below T-N exhibit a hysteretic behavior indicating the existence of some ferromagnetic correlation. This behavior is suppressed by high applied fields. The Fe-57 Mossbauer spectrum measured at 4.2 K for Sr2LaFe3O9 indicates two superimposed hyperfine fields of 260 and 450 kOe with area ratios Of 1/3 and 2/3, respectively, consistent with previous measurements. (C) 1996 American Institute of Physics.