Magnetic structure of (Basub(1-x)Srsub(x))2Zn2Fe12O22 (x = 0 - 1.0)

Neutron and X-ray diffraction studies and magnetization measurements were carried out on single crystals of (Basub(1-x)Srsub(x))2Zn2Fe12O22. The substitution of Ba by Sr produces two effects on the crystal structure: a lattice deformation around the Sr ions and a redistribution of the Zn and Fe ions in the tetrahedral sites. The magnetic structure is analyzed in consideration of these effects: Spins are bunched in the form of ferrimagnet in the every (Tsub(1/2)STsub(1/2)) block and the bunched spins make an angle phisub(o) between the adjacent (Tsub(1/2)STsub(1/2)) blocks. At 294 K, the turn angles phisub(o)'s are found to be 00 (ferromagnetic), 00<phisub(o)<1800 (helical) and 1800 (antiferromagnetic) for 0<=x<=0.5, 0.5<x<0.8 and 0.8<=x<=1.0, respectively. A brief discussion on the exchange interaction of this spin system is given. (author)