Magnetic transition temperatures follow crystallographic symmetry in samarium under high-pressures and low-temperatures

Fluids at high pressures and temperatures

With high pressures, supercritical fluids can be studied over a very wide range of density. Fluids with strongly interacting polar molecules for example water are of particular interest. Results for several thermophysical properties are discussed. Density, dielectric constant and self—ionization of water have been determined or predicted to 1000 °C. Beyond 20 GPa very hot water appears to becom...

Novel broken symmetry phase from N(2)O at high pressures and high temperatures.

Simple molecular solids become unstable at high pressures, typically transforming to dense framework and/or metallic structures. We report formation of an unusual ionic solid NO(+)NO(3)(-) (nitrosonium nitrate) from N(2)O at pressures above 20 GPa and temperatures above 1000 K. Synchrotron x-ray diffraction indicates that the compound crystallizes with a structure related to the aragonite form ...

Electrical conductivity of wadsleyite at high temperatures and high pressures

New phases of N2O4 at high pressures and high temperatures

High P–T studies of molecular N2O4 using Raman, synchrotron infrared, and X-ray diffraction measurements reveal several new phenomena. Significant changes in the vibrational spectra indicate a phase transition at about 12 GPa. The X-ray diffraction measurements show that the material remains cubic through the transition. We ascribe the transition to a change in the molecular geometry of N2O4 wi...

High magnetic field corrections to resistance thermometers at low temperatures