CHEMISTRY AND MATERIAL SCIENCE

Formation of NH$_4$MgF$_3$ and MgF$_2$ nanoparticles from magnesium hydroxycarbonate in ammonium hydrofluoride melt

A. A. Luginina^a, A. A. Alexandrov^ab, D. S. Yasyrkina (Los')^a, Yu. A. Ermakova^a, V. V. Tapero^ac, S. V. Kuznetsov<sup>a

a</sup> Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
^b Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
^c Department of Materials Science of Semiconductors and Dielectrics, National University of Science and Technology (MISIS), Moscow, Russia

Abstract: Ammonium fluorometalates with the perovskite structure NH$_4$MF$_3$ (M = 3d metals) are used for cathode materials and NH$_4$MgF$_3$ is used for solid electrolytes. There is only fragmentary information in the literature about the production of NH$_4$MgF$_3$ powder without available X-ray diffraction data. The conditions enable the synthesis of single-phase NH$_4$MgF$_3$ powder are proposed by reaction of magnesium hydroxycar-bonate with ammonium hydrofluoride melt at a temperature of 220$^\circ$C. It has been established that the process is two-stage: the first reaction is the formation of the(NH$_4$)$_2$MgF$_4$ compound and the second reaction is the decomposition of (NH$_4$)$_2$MgF$_4$ at a temperature of 220$^\circ$C to NH$_4$MgF$_3$. Upon decomposition of NH$_4$MgF$_3$, anhydrous MgF$_2$ nanoparticles (28 $\pm$ 7 nm) are formed. The proposed method for obtaining single-phase NH$_4$MgF$_3$ opens up opportunities for studying its functional properties.

Keywords: ammonium fluorometalate, cubic perovskite structure, magnesium fluoride, nanoscale powders, NH$_4$MgF$_3$, ammonium hydrofluoride.

Received: 14.11.2025
Revised: 19.11.2025
Accepted: 04.12.2025

Language: English

DOI: 10.17586/2220-8054-2025-16-6-897-907