Pressure-induced phase changes in natural fluorapophyllite-(K) studied by Raman spectroscopy.

The high-pressure Raman spectra in the low-wavenumber region (50-1200 cm) and the hydroxyl stretching vibration region (2600-3800 cm) of fluorapophyllite-(K) were collected in the interval of 0.0-50.7 GPa.

Structural properties of PbVO3 perovskites under hydrostatic pressure conditions up to 10.6 GPa.

High-pressure synchrotron x-ray powder diffraction experiments were performed on PbVO(3) tetragonal perovskite in a diamond anvil cell under hydrostatic pressures of up to 10.6 GPa at room temperature. The compression behavior of the PbVO(3) tetragonal phase is highly anisotropic, with the c-axis being the soft direction.

Large volume collapse observed in the phase transition in cubic PbCrO3 perovskite.

When cubic PbCrO(3) perovskite (Phase I) is squeezed up to approximately 1.6 GPa at room temperature, a previously undetected phase (Phase II) has been observed with a 9.8% volume collapse.

[Raman characterization of rutile phase transitions under high-pressure and high-temperature].

The pressure-induced phase transition of rutile-structured TiO2 was investigated by in-situ Raman spectrum method in a laser-heated diamond anvil cell (DAC). The experiment was conducted at 35 GPa under quasihydrostatic conditions using argon as medium. At room temperature, the rutile-type TiO2 begins to transform to baddeleyite-type phase at 13.

[Infrared spectroscopic study of Changbaishan diatomite].

Changbaishan diatomite was treated under the conditions of temperature from 100 to 1330 degrees C, and examined by infrared spectroscopy applying the KBr-technique. In the range from 250 to 1500 cm(-1), the spectra of the samples at 100 to 1100 degrees C show the same three characteristic broad bands at 1100, 801 and 471 cm(-1), which are similar to amorphous silica. Besides the above three broad bands, the spectra of 1200 and 1330 degrees C treated samples exhibit three new bands at 618, 386 and 301 cm(-1), which indicate that the diatornite transforms into cristobalite.

High-temperature and high-pressure cubic zirconia anvil cell for Raman spectroscopy.

A simple and inexpensive cubic zirconia anvil cell has been developed for the performance of in situ Raman spectroscopy up to the conditions of 500 degrees C and 30 kbar pressure. The design and construction of this cell are fully described, as well as its applications for Raman spectroscopy. Molybdenum heater wires wrapped around ceramic tubes encircling two cubic zirconia anvils are used to heat samples, and the temperatures are measured and controlled by a Pt-PtRh thermocouple adhered near the sample chamber and an intelligent digital control apparatus.