Powder X-ray diffraction (XRD) patterns of the as-synthesized and heated samples were recorded on a D8 Advance powder diffractometer (Bruker, Karlsruhe, Germany) with Bragg–Brentano geometry using CuKα radiation in the range 2θ = 10°–70° using a step size of 0.02° and an accumulated time per step of 35 s. Phase identification was carried out using the PDF-4 database (ICDD, Release 2011). The unit cell parameters, crystallite size, and phase concentrations were determined using the Rietveld method [36 (link)] using Topas 4.2 software (Bruker, Karlsruhe, Germany). The fundamental parameter approach was used to account for the instrumental contribution.
Fourier transform infrared (FTIR) spectra of the powders were recorded on an Infralum FT-801 spectrometer (Simex, Novosibirsk, Russia) in the wavelength range 550–4000 cm−1. Pellets made up of a 4 mg sample and 540 mg of KBr were used for the FTIR study.
Simultaneous thermal analysis (STA) experiments were carried out using an STA 449 F1 Jupiter device (Netzsch, Selb, Germany) equipped with a QMS 403C Aeolos mass spectrometer. The measurements were performed under an argon–oxygen mixture (80:20) at a heating rate of 10 °C/min. The analyzed sample with a mass of 30 mg was placed in a corundum crucible.
Fourier transform infrared (FTIR) spectra of the powders were recorded on an Infralum FT-801 spectrometer (Simex, Novosibirsk, Russia) in the wavelength range 550–4000 cm−1. Pellets made up of a 4 mg sample and 540 mg of KBr were used for the FTIR study.
Simultaneous thermal analysis (STA) experiments were carried out using an STA 449 F1 Jupiter device (Netzsch, Selb, Germany) equipped with a QMS 403C Aeolos mass spectrometer. The measurements were performed under an argon–oxygen mixture (80:20) at a heating rate of 10 °C/min. The analyzed sample with a mass of 30 mg was placed in a corundum crucible.