Variable one-dimensional Manganese(III) chains with bridging fluoride: Synthesis, structures, and magnetic properties

Abstract

Three new manganese(III) fluorides—Na2Ba3Mn4F20 (I), NaBa2Mn3F14(II), and NaBaMnF6(III)—were hydrothermally prepared. The crystal structures of these compounds contain variable one-dimensional (1D) manganese(III) chains with bridging fluoride. I features 1D cis chains composed of corner-sharing, alternating [MnF6]3- octahedra, while III contains trans chains, comprised by corner-sharing uniform [MnF6]3- octahedra. II, however, features 1D diamond-shaped chains, where two octahedra are linked to a single octahedron by trans-vertices. The successful preparation of single-crystal and powdered samples of the pure phase allows us to investigate into the relationship between their low-dimensional structures and magnetic properties. Magnetic measurements revealed a variety of magnetic properties at low temperatures, although predominant antiferromagnetic interactions were observed in the titled compounds at high temperatures. I possess canted antiferromagnetic (AFM) ordering, II shows ferrimagnetic-type long-range ordering, and III displays robust antiferromagnetic behaviour. Additionally, the strength of the magnetic coupling in I and III was analyzed based on the local geometry induced by the Jahn−Teller (JT) effect.