High-pressure high-temperature synthesis of new covalent metals

High-pressure – High-temperature Synthesis of Na6MnO4

Z. Naturforsch. 2009, 64b, 487 – 490; received February 20, 2009 The title compound has been synthesized under 4 GPa and at 500 ◦C from Na2O and MnO as starting materials. Rietveld refinement of the X-ray powder pattern indicates that Na6MnO4 is isostructural to Na6ZnO4 and thus is representing the second manifestation of an “isolated” [MnO4]6− anion after Na14Mn2O9. The compound crystallizes i...

High-pressure / High-temperature Synthesis of Transition Metal Oxide Perovskites

Perovskite and related Ruddlesden-Popper type transition metal oxides synthesised at high pressures and temperatures during the last decade are reviewed. More than 60 such new materials have been reported since 1995. Important developments have included perovskites with complex cation orderings on A and B sites, multiferroic bismuth-based perovskites, and new manganites showing colossal magneto...

Considerations of Well Cementing Materials in High-Pressure, High-Temperature Conditions (RESEARCH NOTE)

As worldwide demand of hydrocarbon is growing fast, the oil and gas companies have been forced to explore reservoirs with more hostile conditions, such as high-pressure, high-temperature conditions. Improved technology, material selection and testing procedures are required to overcome the common problems in these conditions. One of the main phases of well construction is cementing job. Appropr...

High-Temperature Pressure Transducers

Pressure sensing systems operating at temperatures >200 °C are required for a variety of presentand next-generation applications ranging from oil field instrumentation to turbine engine control. Quite often, part or all of the sensing system must be physically removed from the hightemperature environment. In some cases, pressure translating devices and capillary tubes are used to isolate the se...

High-temperature spreading kinetics of metals