Room temperature syntheses and thermal behaviors of hydrogarnets Sr3M2(OH)12 (M = Al, Cr and Fe)

•All starting materials were common metal inorganic salts.•Hydrogarnets were synthesized by solid state reaction at room temperature.•The novel synthesis method has an advantage of quick reaction and easy operation.•As-synthesized hydrogarnets have different morphologies.

Hydrogarnets Sr3M2(OH)12 (M = Al, Cr and Fe) were synthesized through a solid state reaction at room temperature with Al(NO3)3·9H2O, CrCl3·6H2O, FeCl3·6H2O, Sr(NO3)2 and NaOH as the starting materials. All X-ray diffraction (XRD) data of Sr3M2(OH)12 were indexed by the cubic system with the space group of Ia−3d. XRD, differential thermal analysis and thermogravimetric (DTA–TG), and scanning electron microscopy (SEM) were employed to investigate the structural stability, thermal properties and morphologies of Sr based hydrogarnets. The cause of room temperature synthesis and the thermal decomposition behaviors of Sr-based hydrogarnets Sr3M2(OH)12 (M = Al, Cr and Fe) are discussed.