Ferrimagnetic order in Ca[sub 2]FeMoO[sub 6].

The double perovskite Ca[sub 2]FeMoO[sub 6] is a poor metal which orders magnetically at 345 K. The [sup 57]Fe Mo¨ssbauer hyperfine field and isomer shift at 4.2 K (48 T and 0.70 mm/s relative to α-Fe) indicate an Fe[sup 3+] configuration 3d[sup 5↑] which is strongly hybridized with the Mo 4d[sup ↓]t[sub 2g] orbitals. The saturation magnetization of 3.6μ[sub B]/formula is consistent with neutron diffraction measurements which indicate iron and molybdenum moments of 4.0(1) and -0.2(3)μ[sub B] per iron or molybdenum, respectively. The sample exhibits approximately 6% cation disorder relative to the ideal NaCl-type order of Fe and Mo in the double perovskite structure. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]