Raman scattering study of phase transition in Lu ₂ O ₃ –Ta ₂ O ₅

Abstract

The lutetium tantalate compounds obtained from Lu2O3–Ta2O5 with a molar ratio of 0.515:0.485 were studied by Raman scattering and x-ray diffraction. The results of the room temperature Raman scattering indicate that the sample has a phase transition between 1830 °C and 1872 °C, the polycrystalline is a mixture of M′-LuTaO4 and when it is prepared at 1830 °C, and a mixture of M-LuTaO4(B112/b) and when it is prepared at above 1872 °C. The sample melts at a temperature of 2050 °C. The phase transition of the sample prepared at 2050 °C was also investigated by the high-temperature Raman spectra, and the result indicates that no phase transition occurs between room temperature and 1400 °C, which is consistent with the results from the x-ray diffraction.

Controlled synthesis of ferromagnetic MnSe x particles

“…Furthermore, such a phase transition will be much easier at high reaction temperature in an autoclave. [33][34][35] However, when the pH values of the solutions are lower than 7, this phase transition cannot be fully completed, even with a long reaction time (48 h) or high reaction temperature (240 • C). The solution always contains a mixture of MnSe 2 and MnSe particles.…”

FDTD simulation study of size/gap and substrate-dependent SERS activity study of Au@SiO 2 nanoparticles

“…[1] Because it has high detection sensitivity, SERS technique has been widely applied to food safety, [2] electrochemistry, [3] and other fields. [4] As currently understood, SERS enhancement mode mainly includes electromagnetic (EM) coupling enhancement and chemical enhancement (CE). [5][6][7][8] The EM mechanism describes the enhanced local EM fields due to resonant excitation of plasma in the metallic nanostructure surface.…”