Study of the Phase-Evolution Mechanism of an Fe-Se System at the Nanoscale: Optimization of Synthesis Conditions for the Isolation of Pure Phases and Their Controlled Growth

Monika Ghalawat; Pankaj Poddar

doi:10.1021/acs.langmuir.9b03643

Study of the Phase-Evolution Mechanism of an Fe-Se System at the Nanoscale: Optimization of Synthesis Conditions for the Isolation of Pure Phases and Their Controlled Growth

Langmuir. 2020 Mar 3;36(8):2012-2022. doi: 10.1021/acs.langmuir.9b03643. Epub 2020 Feb 12.

Authors

Monika Ghalawat¹, Pankaj Poddar¹

Affiliation

¹ Physical & Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.

PMID: 32011144
DOI: 10.1021/acs.langmuir.9b03643

Abstract

The iron selenide (Fe-Se) family of nanoparticles (Fe_xSe_y-where x/y ranges from 1:2 to 1:1) has been fabricated by a thermal decomposition method. The control over solution chemistry has been developed by intensively investigating the effect of reaction parameters by means of wide-angle X-ray scattering, leading to the rich insights into the phase-evolution mechanism of the Fe-Se system. The phase transformation followed the FeSe₂ → Fe₃Se₄ → Fe₇Se₈ → FeSe sequence in the temperature range of 110-300 °C. The deep mechanistic insight helped in the identification of optimized conditions needed to crystallize the individual phase of the Fe-Se system as well as control of the morphology, crystalline phase purity, and thermal stability of the obtained Fe-Se nanoparticles.