Thermo mass photo

The Ba₇Nb₄MoO₂₀·0.15 H₂O samples were prepared by the solid-state reaction method. High-purity (>99.9%) BaCO₃, Nb₂O₅ and MoO₃ were mixed as ethanol slurries and ground as dry powders using an agate mortar and pestle. The obtained powders were calcined at 900 °C for 12 h for decarbonation. The materials thus obtained were crushed and ground into fine powders in an agate mortar for 1 h as dried powders and ethanol slurries. The resultant powders were uniaxially pressed at 150 MPa and then sintered in air at 1100 °C for 24 h. The sintered pellets were crushed and ground into fine powders for X-ray powder diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES, Shimadzu ICPS-8100 spectrometer), and TG-MS measurements. The ICP-AES results indicated that the cation molar ratio of Ba₇Nb₄MoO₂₀·0.15 H₂O was Ba: Nb: Mo = 6.89(12): 4.078(18): 1.034(10), which is consistent with the nominal composition. TG-MS analyses of Ba₇Nb₄MoO₂₀·0.15 H₂O were performed using RIGAKU Thermo Mass Photo under He flows at a heating rate of 20 K min^–1 up to 900 °C. The Raman spectrum of Ba₇Nb₄MoO₂₀·0.15 H₂O was collected using an NRS-4100 (JASCO Co.) instrument with an excitation wavelength of 532 nm.

TG-MS was conducted using a Thermo Mass Photo which was purchased from Rigaku (Tokyo, Japan). A 3 mg–10 mg sample was added into the alumina crucible. The heating process was from room temperature to 900 °C under N₂ atmosphere with the heating rate of 10 °C/min.