Structural diversity dependent cation incorporation into magnetic Cr–Se nanocrystals

Chromium selenide (Cr-Se)-based low-dimensional materials have attracted significant attention in spintronics because of their diverse structure- and composition-dependent magnetic properties. While significant progress has been made in fabricating the Cr-Se family of nanomaterials through techniques like chemical vapor deposition, the synthesis of Cr-Se nanocrystals (NCs) via colloidal methods remains underexplored. In this work, we demonstrate the robust colloidal synthesis approach for producing Cr₂Se₃ and Cr₃Se₄ NCs with distinct morphologies by varying the Cr precursors and ligands. Cr-Se NCs can serve as templates for cation exchange (CE) reactions involving monovalent Cu⁺ and Ag⁺, divalent Zn²⁺ and Cd²⁺, and trivalent In³⁺, facilitating the creation of a diverse library of metal selenide NCs and nanoheterostructures. Our findings highlight how the outcomes of CE reactions are influenced by the structure of various Cr-Se phases. Furthermore, the magnetic properties of the as-synthesized Cr-Se NCs and their derivative CuCrSe₂ were investigated. Our work provides a robust synthesis route for the Cr-Se class of magnetic nanomaterials and a platform for creating a diverse range of functional metal selenide NCs via CE reactions.