Two polymorphous lithium stannoferrites LiFeSnO4: A ramsdellite-type and a hexagonal close-packed structure

The stannoferrite LiFeSnO4 has been synthesize and investigated by X-ray diffraction and electron microscopy. Two forms have been characterized. High-temperature LiFeSnO4 is orthorhombic, isotypic with MnO2 ramsdellite: a = 3.066 A ̊, b = 5.066 A ̊, c = 9.874 A ̊; low-temperature LiFeSnO4 is hexagonal with a = 6.012Z A ̊, c = 9.776 A ̊ and isotypic with Li1.6Zn1.6Sn2.8O4. Both structures have been refined. This polymorphous transition and relationships between the two forms and spinel structure are discussed. © 1981.