scholarly journals High-pressure, high-temperature molecular doping of nanodiamond

2019 ◽  
Vol 5 (5) ◽  
pp. eaau6073 ◽  
Author(s):  
M. J. Crane ◽  
A. Petrone ◽  
R. A. Beck ◽  
M. B. Lim ◽  
X. Zhou ◽  
...  
Keyword(s):  
High Pressure ◽  
Ion Implantation ◽  
High Pressures ◽  
Noble Gas ◽  
Color Centers ◽  
Vacancy Defects ◽  
High Pressure High Temperature ◽  
Pressure Medium ◽  
Optical Pressure ◽  
Pressure Metrology

The development of color centers in diamond as the basis for emerging quantum technologies has been limited by the need for ion implantation to create the appropriate defects. We present a versatile method to dope diamond without ion implantation by synthesis of a doped amorphous carbon precursor and transformation at high temperatures and high pressures. To explore this bottom-up method for color center generation, we rationally create silicon vacancy defects in nanodiamond and investigate them for optical pressure metrology. In addition, we show that this process can generate noble gas defects within diamond from the typically inactive argon pressure medium, which may explain the hysteresis effects observed in other high-pressure experiments and the presence of noble gases in some meteoritic nanodiamonds. Our results illustrate a general method to produce color centers in diamond and may enable the controlled generation of designer defects.

scholarly journals The Takahashi–Bassett Era of Mineral Physics at Rochester in the 1960s

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 344
Author(s):  
William A. Bassett
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Faculty Position ◽  
Mineral Physics ◽  
High Pressure High Temperature ◽  
High Pressures And Temperatures ◽  
The 1960S ◽  
Talented Students ◽  
The University

The late Taro Takahashi earned a particularly well-deserved reputation for his research at Lamont Geological Observatory on carbon dioxide and its transfer between the atmosphere and the oceans. However, his accomplishments in Mineral Physics, the field embracing the high-pressure–high-temperature properties of materials, has received less attention in spite of his major contributions to this emerging field focused on the interiors of Earth and other planets. In 1963, I was thrilled when he was offered a faculty position in the Geology Department at the University of Rochester, where I had recently joined the faculty. Taro and I worked together for the next 10 years with our talented students exploring the blossoming field just becoming known as Mineral Physics, the name introduced by Orson Anderson and Ed Schreiber, who were also engaged in measuring physical properties at high pressures and temperatures. While their specialty was ultrasonic velocities in minerals subjected to high pressures and temperatures, ours was the determination of crystal structures, compressibilities, and densities of such minerals as iron, its alloys, and silicate minerals, especially those synthesized at high-pressure, such as silicates with the spinel structure. These were materials expected to be found in the Earth’s interior and could therefore provide background for the interpretation of geophysical observations.

Formation of two crystal modifications of Fe7C3−x at 5.5 GPa

2019 ◽  
Vol 52 (6) ◽  
pp. 1378-1384
Author(s):  
Sergey Gromilov ◽  
Anatoly Chepurov ◽  
Valeri Sonin ◽  
Egor Zhimulev ◽  
Aleksandr Sukhikh ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Experimental Studies ◽  
X Ray Diffraction ◽  
High Iron Content ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Micro Analysis ◽  
Crystal Modifications ◽  
High Pressure Apparatus

The Fe–C system, which is widely used to grow commercial high-pressure–high-temperature diamond monocrystals, is rather complicated due to the formation of carbides. The carbide Fe3C is a normal run product, but the pressure at which Fe7C3 carbide becomes stable is a subject of discussion. This paper demonstrates the synthesis of Fe7C3 carbide and its detailed study using single-crystal and powder X-ray diffraction, as well as electron probe micro-analysis and scanning electron microscopy. The experiments were performed using a multiple-anvil high-pressure apparatus of `split-sphere' (BARS) type at a pressure of 5.5 GPa and a temperature of 1623 K. Our results show that in the Fe–C system, in addition to diamond, a phase that corresponds to the Fe7C3 carbide was synthesized. This means that both carbides (Fe7C3 and Fe3C) are stable at 5.5 GPa. Two crystal phases are described, Fe14C6 and Fe28C12−x . Fe14C6 is based on the well known rhombic structure of Fe7C3, while Fe28C12−x has a different packing order of Fe6C polyhedrons. The results obtained in this study should be taken into account when synthesizing and growing diamond at high pressures and temperatures in metal–carbon systems with a high iron content, as well as when conducting experimental studies on the synthesis of diamond directly from carbide.

Spectroscopy at High Pressures—Status Report and Update of Instrumental Techniques

1974 ◽  
Vol 28 (6) ◽  
pp. 505-516 ◽  
Author(s):  
John R. Ferraro ◽  
Louis J. Basile
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Pressures ◽  
Status Report ◽  
Future Outlook ◽  
Optical Link ◽  
Interferometric Technique ◽  
Pressure Calibration ◽  
Calibration Methods ◽  
Optical Pressure

A status report and update of the instrumentation necessary to obtain spectra of molecules at high pressures are presented. The optical pressure cells used, the spectrophotometer needed to obtain the spectra, the optical link between the two, high pressure spectroscopic windows, pressure calibration methods, and future outlook of the technique will be determined. The use of the high pressure cells with the interferometric technique and for Raman spectroscopy is outlined.

Advances in Computation of Temperature-Pressure Phase Diagrams of High-Pressure Nitrides

2008 ◽  
Vol 403 ◽  
pp. 77-80 ◽  
Author(s):  
Peter Kroll
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Elevated Temperature ◽  
Total Energy ◽  
Phase Diagrams ◽  
High Pressures ◽  
First Principle ◽  
Energy Calculations ◽  
High Pressure High Temperature ◽  
Pressure Phase

A combination of first-principle and thermochemical calculations is applied to compute the phase diagrams of rhenium-nitrogen and of ruthenium-nitrogen at elevated temperature and high pressure. We augment total energy calculations with our approach to treat the nitrogen fugacity at high pressures. We predict a sequential nitridation of Re at high-pressure/high-temperature conditions. At 3000 K, ReN will form from Re and nitrogen at about 32 GPa. A ReN2 with CoSb2-type structure may be achieved at pressures exceeding 50 GPa at this temperature. Marcasite-type RuN2 will be attainable at 3000 K at pressures above 30 GPa by reacting Ru with nitrogen.

Solid krypton in MgO

1992 ◽  
Vol 7 (12) ◽  
pp. 3171-3174 ◽  
Author(s):  
M. Grant Norton ◽  
C. Barry Carter ◽  
Elizabeth L. Fleischer ◽  
James W. Mayer
Keyword(s):  
High Pressure ◽  
Electron Diffraction ◽  
Ion Implantation ◽  
Single Crystal ◽  
Magnesium Oxide ◽  
Room Temperature ◽  
Noble Gas ◽  
Lattice Parameter ◽  
Solid Krypton ◽  
Measured Lattice Parameter

Recent work by the authors has been extended to demonstrate the formation of solid krypton in single-crystal magnesium oxide. The solid inclusions, which were formed by ion implantation at room temperature, have been identified by electron diffraction. The formation of solid noble gas inclusions at room temperature indicates that they were under a high pressure. This pressure was determined, based on the measured lattice parameter, to be 1.7 GPa.

scholarly journals Correlation of metabasic rocks from metamorphic soles of the Dinaridic and the Western Vardar zone ophiolites (Serbia): Three contrasting pressure-temperature-time paths

2012 ◽  
pp. 61-85
Author(s):  
Danica Sreckovic-Batocanin ◽  
Nada Vaskovic ◽  
Vesna Matovic ◽  
Violeta Gajic
Keyword(s):  
High Pressure ◽  
Tectonic Setting ◽  
Granulite Facies ◽  
Oceanic Lithosphere ◽  
Medium Temperature ◽  
Vardar Zone ◽  
High Pressure High Temperature ◽  
Pressure Medium ◽  
Compositional Variations ◽  
Temperature Time

The field, petrological-mineralogical, geochemical and geochronological data of the metamorphic sole rocks recorded beneath the Fruska Gora, Povlen (Tejici), Stolovi and Banjska ophiolites in the Western Vardar Zone (WVZ) and beneath the Zlatibor, Bistrica, Sjenicki Ozren and Brezovica ophiolites in the Dinaridic ophiolite belt (DOB) in Serbia are compared. The focus has been made on metabasic rocks formed in contact with the oceanic crust members: cumulate gabbro and basalts of SSZ-type with E-MORB and OIB-signature and more evolved tholeiitic basalts of MOR-affinity. Amphibole, the major phase formed from the mafic sole components, depending on pressure-temperature conditions exhibits compositional variations. According to mineral assemblages, estimated P-T conditions and ages, the potential P-T paths are given: high pressure - low temperature blueschist facies assemblage (7-9 kbar and ~400?C and <300-350?C and 4-8 kbar), recorded only in the metamorphic sole at the Fruska Gora (WVZ); high pressure - high temperature amphibolite to granulite facies (8-10 kbar and >700-850?C), recorded in both domains, the WVZ (Banjska) and the DOB (Bistrica, Sjenicki Ozren, Brezovica) and medium pressure - medium temperature amphibolite facies assemblages (~3.5-7 kbar and >350-650?C) recognized in the WZV (Tejici, Devovici) and the DOB (Zlatibor). The peak metamorphic conditions point to depths of the oceanic lithosphere detachment and its initial cooling at 10-30 km, but the ages and tectonic setting of ophiolites remain poorly constrained. The summarized data may be used as an important key in geodynamic evolution of the Mesozoic Tethyan ophiolites.

Near Infrared Absorption of Pure n-Heptane between 5000 cm 1 and 6500 cm-1 to High Pressures and Temperatures

1983 ◽  
Vol 38 (5) ◽  
pp. 528-532 ◽  
Author(s):  
M. Buback ◽  
A. A. Harfoush
Keyword(s):  
High Pressure ◽  
Infrared Absorption ◽  
Near Infrared ◽  
High Pressures ◽  
Kinetic Studies ◽  
Molar Absorptivity ◽  
High Pressure High Temperature ◽  
High Pressures And Temperatures ◽  
Combination Mode ◽  
Better Than

The near infrared absorption of pure n-heptane between 5000 cm-1 and 6500 cm-1 was measured up to 250 °C and to pressures of 2000 bar. The procedure for measuring vibrational intensities at high pressures and temperatures with a precision of better than ± 1% is described. The integrated “molar absorptivity of the combination mode va + vs of the methylene stretching fundamentals turns out to be independent of temperature and density. This offers important applications for high-pressure high-temperature thermodynamic and kinetic studies via quanti­tative near infrared spectroscopy.

scholarly journals High-pressure / High-temperature Synthesis and Characterization of Boron-doped Diamond

2006 ◽  
Vol 61 (12) ◽  
pp. 1561-1565 ◽  
Author(s):  
Natalia Dubrovinskaia ◽  
Leonid Dubrovinsky ◽  
Nobuyoshi Miyajima ◽  
Falko Langenhorst ◽  
Wilson A. Crichton ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Pressures ◽  
Direct Reaction ◽  
X Ray Diffraction ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

Bulk samples (with volumes up to ~ 7.5 mm3) of boron-doped diamonds (BDD) were synthesized by means of direct reaction between boron carbide and graphite in a multianvil apparatus at high pressures and high temperatures (HPHT). X-ray diffraction data revealed the presence in BDD of a very small amount of a highly boron-enriched phase (B50C2) and traces of the B13C2 used as an initial material. The absence of B50C2 in the product of treatment of pure B13C2 under the same HPHT conditions suggests that boron-rich carbides exsolute from diamond on quenching leading to boron depletion of the diamond matrix. These observations imply that boron solubility in diamond increases at high pressure and high temperature. This result may have important implications for the understanding of the mechanism of boron incorporation into diamond at HPHT synthesis and for the interpretation of the data on superconductivity of polycrystalline BDD.

scholarly journals Oxidation of High Yield Strength Metals Tungsten and Rhenium in High-Pressure High-Temperature Experiments of Carbon Dioxide and Carbonates

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 676 ◽  
Author(s):  
Raquel Chuliá-Jordán ◽  
David Santamaría-Pérez ◽  
Tomás Marqueño ◽  
Javier Ruiz-Fuertes ◽  
Dominik Daisenberger
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Yield Strength ◽  
High Pressures ◽  
Chemical Reactivity ◽  
High Yield ◽  
Reaction Products ◽  
High Yield Strength ◽  
High Pressure High Temperature ◽  
Diamond Anvil

The laser-heating diamond-anvil cell technique enables direct investigations of materials under high pressures and temperatures, usually confining the samples with high yield strength W and Re gaskets. This work presents experimental data that evidences the chemical reactivity between these refractory metals and CO2 or carbonates at temperatures above 1300 °Ϲ and pressures above 6 GPa. Metal oxides and diamond are identified as reaction products. Recommendations to minimize non-desired chemical reactions in high-pressure high-temperature experiments are given.

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