Some chalcogenides syntheses via soft chemistry

Most of the examples of chalcogenides syntheses via soft chemistry arerelated to deintercalation or ion condensation. The first process is illustrated by lithium deintercalation from the lamellar Li2FeS2 compound and the investigation of the LixFeS2 (0&lex&le2). For 1&lex&le2, lithium is removed from tetrahedra and iron is oxidized from its pristine oxidation state II to III. For lower lithium content, lithium is extracted from octahedra and the redox process involves sulfur oxidation by sulfur pairing. For 1&lex&le1.5, a structural rearrangement occurs that stabilizes the partially deintercalated slab through a new distribution of iron atoms in tetrahedral sites. The ion condensation process is illustrated by the synthesis of the amorphous nickel thiophosphate a-NiPS3. An XAS study at the nickel K edge allows to define precisely the condensation process and to confirm the formation of very small particles, in agreement with XRD, HREM and magnetic susceptibility measurements.