James Fulton Fleischer

The diamond 13C/12C isotope Raman pressure sensor system for high-temperature/pressure diamond-anvil cells with reactive samples

By using a thin 13C diamond chip together with a 12C diamond chip as sensors, the diamond Raman spectra provide the means to measure pressure precisely (±0.3 GPa) at any temperature (10–1200 K) and simultaneous hydrostatic (or quasihydrostatic) pressure (0–25 GPa) for any sample compatible with an externally heated diamond-anvil cell. Minimum interference between the Raman spectrum from the diamond anvils and those of the pressure sensors is obtained by measuring pressures with the Raman signal from the 13C diamond chip up to 13 GPa, and that from the 12C chip above 10 GPa. The best crystallographic orientation of the diamond anvils is with the [100] direction along the direction of applied force, in order to further minimize the interference. At 298 K, the pressure dependence of the 13C diamond first-order Raman line is given by ν(P)=νRT+aP for 91 at. % 13C diamond, where νRT(13C)=1287.79±0.28 cm−1 and a(13C)=2.83±0.05 cm−1/GPa. Analysis of values from the literature shows that the pressure dependence of...

The system Li3BN2 at high pressures and temperatures

Abstract The system Li3BN2 was studied over the pressure and temperature range from 10 to 65 kb and 300–1900°C, respectively. The stability region of a quenchable high pressure modification, Li3BN2(W), was defined, and the data also suggest the possibility of another nonquenchable high pressure modification. Li3BN2(W) is the phase which appears to be in equilibrium with borazon (cubic BN) during growth of this phase from the system Li3N-BN, and the P-T data obtained on the melting of Li3BN2(W) are useful for defining the growth conditions for borazon.

The determination of oxygen in titanium: Vacuum fusion with a platinum bath

Abstract Oxygen can be determined in titanium accurately by vacuum fusion with a platinum bath. The platinum bath is preferred to an iron bath or dry bath since more samples can be analysed in a bath without interference from gettering and solidification of the bath. The blank from adding iron or tin with the sample is eliminated.

Phase equilibria and crystal growth in the systems PbO·PbCrO4PbO·PbMoO4, PbO·PbCrO4PbO·PbWO4 and PbO·PbCrO4PbO·PbSO4

Abstract PbO·PbCrO4 is a paint pigment with interesting semiconductor and thermochromic properties. Preparatory to crystal growth and property measurements of this material, phase equilibria studies were made in the systems PbO·PbCrO4-PbO·PbMoO4, PbO·PbCrO4-PbO·PbWO4 and PbO·PbCrO4-PbO·PbSO4. In each case complete miscibility in the solid and liquid states was found. The small separation between solidus and liquidus in each system and rapid attainment of equilibrium permits the growth of large homogeneous crystals by pulling from the melt.

Pressure-temperature diagram for the system SrSiO3

Abstract The P-T diagram from the system SrSiO 3 was determined by equilibration and quenching of SrSiO 3 in a “belt”-type high-pressure apparatus up to nearly 70 kb and 1600°C. In agreement with others, three crystalline phases were found to be quenchable and are in equilibrium at about 47 kb and 750°C. The low-temperature form has a melting curve with a negative slope as predicted by Buckner and Roy (1).