Controllable hydrothermal synthesis of star-shaped Sr3Fe2(OH)12 assemblies and their thermal decomposition and magnetic properties--颗粒学报PARTICUOLOGY

Zhang, H., Wang, T., Chen, X., & Zhu, W. (2016). Controllable hydrothermal synthesis of star-shaped Sr3Fe2(OH)12 assemblies and their thermal decomposition and magnetic properties. Particuology, 24, 210-215. https://doi.org/10.1016/j.partic.2015.08.002

Controllable hydrothermal synthesis of star-shaped Sr₃Fe₂(OH)₁₂ assemblies and their thermal decomposition and magnetic properties

Heng Zhang ^*, Tingting Wang, Xiuping Chen, Wancheng Zhu ^*

Department of Chemical Engineering, Qufu Normal University, Qufu 273165, China

10.1016/j.partic.2015.08.002

Volume 24, February 2016, Pages 210-215

Received 26 April 2015, Revised 4 August 2015, Accepted 9 August 2015, Available online 21 October 2015, Version of Record 21 January 2016.

E-mail: zhangheng@mail.qfnu.edu.cn; zhuwancheng@tsinghua.org.cn

Highlights

• Star-shaped Sr₃Fe₂(OH)₁₂ assemblies were synthesized via a mild hydrothermal route.

• Impurities could be mitigated by increasing the molar ratio of Sr/Fe.

• Thermal decomposition and magnetic properties were investigated.

Abstract

Pure phase star-shaped hydrogarnet Sr₃Fe₂(OH)₁₂ assemblies were synthesized by a mild hydrothermal method (210 °C, 12 h), and the effects of the preparation conditions on the phase composition of the product were investigated. It was found that the impurity phases could be decreased or eliminated by increasing the molar ratio of Sr²⁺ to Fe³⁺, and that high temperatures favored the formation of Sr₃Fe₂(OH)₁₂ and reduced the concentration of CO₃^2–-containing byproducts. The thermal decomposition of the star-shaped Sr₃Fe₂(OH)₁₂ assemblies was examined, and the results showed that the dehydration process at higher temperatures is accompanied by the formation of SrFeO₃_–δ. Above 655 °C, a solid state reaction between the SrFeO_3–δ and Sr(OH)₂ or SrCO₃ results in the formation of Sr₄Fe₃O_10–δ.The magnetic properties of the as-synthesized Sr₃Fe₂(OH)₁₂ and of samples calcined at different temperatures were assessed. A sample calcined at 575 °C exhibited greatly enhanced ferromagnetic properties, with a remanent magnetization of 1.28 emu/g and a coercivity of 4522.1 Oe at room temperature.

Graphical abstract

Keywords

Hydrogarnet; Hydrothermal; Star-shaped; Thermal decomposition; Magnetic property

文章导读