부산대학교 도서관

A polycrystalline sample of LaSr 2 Cr 2 SbO 9 has been synthesised using a standard ceramic method and characterized by x-ray and neutron diffraction, magnetometry and electron microscopy. The perovskite-related compound crystallises in the triclinic space group I 1 ̅ with unit cell parameters of a =5.5344(6) Å, b =5.5562(5) Å, c =7.8292(7) Å, α=89.986(12)°, β =90.350(5)° and γ=89.926(9)° at room temperature. The two crystallographically-distinct, six-coordinate cation sites are occupied by Cr 3+ and Sb 5+ in ratios of 0.868(2):0.132(2) and 0.462(2):0.538(2). Ac and dc magnetometry revealed that LaSr 2 Cr 2 SbO 9 is ferrimagnetic below 150 K with a magnetisation of ~1.25 µ B per formula unit in 50 kOe at 5 K. Neutron diffraction showed that the cations on the two sites order in a G-type arrangement with a mean Cr 3+ moment of 2.17(1) µ B at 5 K, consistent with a magnetisation of 1.32 µ B per formula unit. [ABSTRACT FROM AUTHOR]