Fabrication of Colloidal Cesium Metal Halide (CsMX: M = Fe, Co, and Ni) Nanoparticles and Assessment of Their Thermodynamic Stability by DFT Calculations

Hyo-Geun Kwon; Jehyeon Ryu; Jong-Goo Park; Sang Woo Park; O-Pil Kwon; Ki-Ha Hong; Sang-Wook Kim

doi:10.1021/acs.inorgchem.2c02155

Fabrication of Colloidal Cesium Metal Halide (CsMX: M = Fe, Co, and Ni) Nanoparticles and Assessment of Their Thermodynamic Stability by DFT Calculations

Inorg Chem. 2022 Sep 12;61(36):14361-14367. doi: 10.1021/acs.inorgchem.2c02155. Epub 2022 Sep 1.

Authors

Hyo-Geun Kwon¹, Jehyeon Ryu¹, Jong-Goo Park², Sang Woo Park², O-Pil Kwon¹, Ki-Ha Hong², Sang-Wook Kim¹

Affiliations

¹ Department of Molecular Science and Technology, Ajou University, Suwon 16499, Republic of Korea.
² Department of Materials Science and Engineering, Hanbat National University, Daejeon 34158, Republic of Korea.

PMID: 36047720
DOI: 10.1021/acs.inorgchem.2c02155

Abstract

We synthesized colloidal cesium metal halide CsMX (M = Fe, Co, Ni; X = Cl, Br) nanoparticles (NPs) and assessed their crystal stability by density functional theory (DFT) calculations. We successfully synthesized Cs₃FeCl₅, Cs₃FeBr₅, Cs₃CoCl₅, Cs₃CoBr₅, CsNiCl₃, and CsNiBr₃ NPs. CsMX NPs with Fe and Co exhibited Cs₃M₁X₅ and Cs₂M₁X₄ structures depending on the reaction conditions; however, CsNiX NPs exhibited only the CsNiX₃ structure. The differences in structural stability by central metal ions were explained using spin-polarized DFT calculations. The analysis revealed tetragonal Cs₃M₁X₅ and orthorhombic Cs₂M₁X₄ structures to have similar thermodynamic stabilities in the case of Fe and Co, whereas the hexagonal CsMX₃ structure in the case of Ni was the most stable. Moreover, the calculation results were the same as the experimental results. In particular, cobalt-related Cs₃CoBr₅ NPs easily developed into Cs₂CoCl₄ nanorods with an increase in temperature.