ARSENIDES OF THE TRANSITION METALS: II. THE NICKEL ARSENIDES

1957 ◽  
Vol 35 (10) ◽  
pp. 1205-1215 ◽  
Author(s):  
R. D. Heyding ◽  
L. D. Calvert
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Transition Metals ◽  
Stability Region ◽  
Room Temperature ◽  
Metastable Phase ◽  
The Other ◽  
Incongruent Melting ◽  
Diffraction Patterns ◽  
The Stability

Alloys of nickel and arsenic containing up to 60% As by weight have been studied by means of room temperature and high temperature Debye-Scherrer diagrams. Three compounds have been identified: Ni5As2, Ni12−xAs8 (maucherite), and NiAs (niccolite). The first of these is homogeneous from Ni5As2 to Ni4.8A2 at room temperature, and to Ni4.6As2 above 250 °C., while the latter is homogeneous from NiAs to Ni0.95As. Contrary to expectations the stability region of the compound Ni12−xAs8 is very narrow, and occurs at Ni11As8 rather than at Ni3As2. Evidence is presented in support of Hansen's contention that this compound has an incongruent melting point. Alloys in the region corresponding to Ni4.6As2 undergo two transitions below 200 °C, one of which is martensitic and produces a metastable phase, while the other is believed to result in the formation of a new compound, as yet unidentified. The diffraction patterns are discussed in some detail.

scholarly journals Creep and Material Design

2012 ◽  
Vol 9 (1) ◽  
pp. 169-171
Author(s):  
Ram Oruganti
Keyword(s):  
High Temperature ◽  
Creep Resistance ◽  
Room Temperature ◽  
Shape Change ◽  
Creep Damage ◽  
Material Design ◽  
The Other ◽  
Permanent Shape ◽  
Total Life

When a material is subjected to temperature and stress, it deforms slowly resulting in permanent shape change. If the same amount of stress were applied at room temperature, the material would not budge. This deformation at high temperature under low stresses is called creep. This phenomenon is important for OEM’S like GE etc. since turbine components are exposed to low stress and high temperature and the resulting shape change is not a desirable consequence. Apart from the change in shape, the components can eventually rupture leading to catastrophic consequences. So it is imperative that the nature of this phenomenon is understood well. Some of the questions to be answered are 1) What makes one material more resistant to creep that the other 2) How can a material’s creep resistance be improved 3) How can the current creep damage in a component be measured 4) Is it possible to say what fraction of the total life of a component has been consumed by creep.

ARSENIDES OF TRANSITION METALS: THE ARSENIDES OF IRON AND COBALT

1957 ◽  
Vol 35 (5) ◽  
pp. 449-457 ◽  
Author(s):  
R. D. Heyding ◽  
L. D. Calvert
Keyword(s):  
High Temperature ◽  
Transition Metals ◽  
Room Temperature ◽  
Pressure Data ◽  
Decomposition Pressure

Alloys of cobalt and arsenic containing up to 60% As by weight have been studied by means of room temperature and high temperature Debye–Scherrer diagrams. Two compounds exist at room temperature, Co2As and CoAs, both of which undergo crystallographic transformations at higher temperatures, the former between 400 °C. and 500 °C., the latter at about 950 °C. A third compound, probably Co3AS2, is formed by the reaction of Co2As with CoAs above 940 °C. The structures of these compounds are compared with the structures of the corresponding compounds in the iron/arsenic system. These results indicate the necessity of slight revisions to the Co/As diagram, and raise serious questions in respect of the validity of decomposition pressure data reported recently for cobalt arsenides.

High Temperature Implantation in Graphite

1983 ◽  
Vol 27 ◽  
Author(s):  
G. Braunstein ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
High Temperature ◽  
Radiation Damage ◽  
High Temperatures ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
Rutherford Backscattering ◽  
The Other ◽  
Highly Oriented Pyrolytic Graphite ◽  
Graphite Lattice ◽  
Partial Annealing

ABSTRACTIn previous studies it was found that when highly oriented pyrolytic graphite (HOPG) is implanted at room temperature, the damage caused by the implantation could be completely annealed by heating the sample to temperatures higher than ∼ 2500°C. However at these high temperatures, the implanted species was found to diffuse out of the sample, as evidenced by the disappearance of the impurity peak in the Rutherford backscattering (RBS) spectrum. If, on the other hand, the HOPG crystal was held at a high temperature (≥ 600°C) during the implantation, partial annealing could be observed. The present work further shows that it is possible to anneal the radiation damage and simultaneously to retain the implants in the graphite lattice by means of high temperature implantation (Ti ≥ 450°C) followed by annealing at 2300°C.

Modifications 7 And 8 Of Decagonal AI-Co-Ni

1998 ◽  
Vol 553 ◽  
Author(s):  
S. Ritsch ◽  
K. Hiraga ◽  
C. Beeli ◽  
T. Gödecke ◽  
M. Scheffer ◽  
...  
Keyword(s):  
Rotation Axis ◽  
The Other ◽  
Stability Field ◽  
One Dimensional ◽  
Decagonal Phase ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
The Stability ◽  
Means Of Transmission ◽  
Very High

AbstractBesides the six established decagonal states of the Al-Co-Ni quasicrystal two more modifications have been discovered by means of transmission electron microscopy. One is a pentagonal quasicrystal with a superstructure found in specimens with a very high Co-content and quenched from the highest possible temperature lying within the stability field of decagonal Al-Co-Ni. Its electron diffraction patterns are characterized by a 5-fold rotation axis as a unique symmetry element as well as superstructure reflections similar to those of a related decagonal phase. The other is a one-dimensional quasicrystal closely related to decagonal Al-Co-Ni. The modulation length of 61 Å along the periodic direction in its pseudo 10-fold diffraction patterns can be assumed to be caused by a strong linear, uniform, phason strain in the material.

Carbonyl halides of the Group VI transition metals. IX. Complexes with Bis(diphenylarsino)methane: Some further carbon monoxide carriers

1968 ◽  
Vol 21 (5) ◽  
pp. 1159 ◽  
Author(s):  
MW Anker ◽  
R Colton ◽  
IB Tomkins
Keyword(s):  
Carbon Monoxide ◽  
Transition Metals ◽  
Room Temperature ◽  
Bidentate Ligand ◽  
The Other ◽  
Group Vi ◽  
Mixed Coordination ◽  
Temperature And Pressure

Complexes of the types MX2(CO)3(dam)2 and MX2(CO)2(dam)2 [M = Mo, W; X = Cl, Br; dam = bis(diphenylarsino)methane] have been prepared and characterized. The compounds are all non-electrolytes; in the tricarbonyls both of the potentially bidentate arsenic ligands are in fact acting only as monodentates, but in the dicarbonyls there is mixed coordination with one ligand monodentate and the other bidentate. The dicarbonyl complexes absorb carbon monoxide in solution at room temperature and pressure, a metal-arsenic bond of the bidentate ligand is broken, and the corresponding tricarbonyl compound is produced. The reaction is readily reversible; thus the system is an example of a carbon monoxide carrier.

scholarly journals The thermal expansion of bismuth by X-ray measurements

1934 ◽  
Vol 143 (849) ◽  
pp. 465-472 ◽  
Keyword(s):  
Thermal Expansion ◽  
Melting Point ◽  
Single Crystals ◽  
Room Temperature ◽  
The Other ◽  
Optical Methods ◽  
Lattice Expansion ◽  
X Ray ◽  
Expansion Curve ◽  
Methods Of Measurement

X-ray measurements recently carried out by the author on the lattice expansion of silver and quartz showed that the coefficients of thermal expansion, over the ranges investigated, are the same as those observed for the specimen as a whole using optical methods. Goetz and Hergenrother, on the other hand, from X-ray measurements on the coefficients of thermal expansion of single crystals of bismuth, claimed to have found a large difference between values obtained by the two methods of measurement. A possible explanatiion of this that their accuracy is not sufficient to establish definitely the deviation of the X-ray measurements from the optical expansion curve. The author has since made X-ray measurements on the expansion of the bismuth lattice from room temperature to just below the melting point, and finds no evidence of such a discrepancy as Goetz and Hergenrother record.

4H-SiC PIN Diode as High Temperature Multifunction Sensor

2017 ◽  
Vol 897 ◽  
pp. 630-633 ◽  
Author(s):  
Shuo Ben Hou ◽  
Per Erik Hellström ◽  
Carl Mikael Zetterling ◽  
Mikael Östling
Keyword(s):  
High Temperature ◽  
Bias Voltage ◽  
Temperature Sensitivity ◽  
Room Temperature ◽  
Optical Sensing ◽  
Temperature Sensing ◽  
The Other ◽  
Pin Diode ◽  
Forward Current

An in-house fabricated 4H-SiC PIN diode that has both optical sensing and temperature sensing functions from room temperature (RT) to 550 °C is presented. The two sensing functions can be simply converted from one to the other by switching the bias voltage on the diode. The optical responsivity of the diode at 365 nm is 31.8 mA/W at 550 °C. The temperature sensitivity of the diode is 2.7 mV/°C at the forward current of 1 μA.

scholarly journals Experimental Investigation of Electro-thermal Stress Impact on SiC-BJTs Electrical Characteristics

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000290-000297
Author(s):  
Thibaut Chailloux ◽  
Cyril Calvez ◽  
Pascal Bevilacqua ◽  
Dominique Planson ◽  
Dominique Tournier
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
Room Temperature ◽  
Thermal Stresses ◽  
Temperature Cycling ◽  
Bipolar Junction Transistors ◽  
Electrical Characteristics ◽  
Switching Operation ◽  
Operation Temperature ◽  
The Stability

The aim of this study consists in investigating the effects of electrical and thermal stresses on SiC n-p-n bipolar junction transistors (BJTs). The stability of the electrical characteristics of BJTs is inspected under switching operation, DC operation, temperature cycling and continuous thermal stress up to 225°C. While switching operation and temperature cycling for several hours lead to significant changes at 25°C, the electrical characteristics were little degraded at high temperature. Besides, DC operation and continuous thermal stress did not result in significant degradation at all, both at room temperature and at high temperature.

scholarly journals Studies on the Stability of Vitamin C at Elevated Concentrations in Canned Tropical Fruit Juices and Nectars

1969 ◽  
Vol 48 (4) ◽  
pp. 327-336
Author(s):  
Abdul R. Rahman ◽  
J. Anziani ◽  
E. Díaz Negrón
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Room Temperature ◽  
Fruit Juices ◽  
The Other ◽  
Tropical Fruit ◽  
The Stability ◽  
Different Levels

Studies were conducted to determine the stability of vitamin C at elevated concentrations in canned tropical fruit juices and nectars. Canned guava nectar, as well as juices of orange, tomato, and pineapple were fortified with ascorbic acid at seven different levels ranging from the original content present in the samples to about 300 mg. per 100 ml. Half of the samples were stored at room temperature and the other similar half at 100°F. for a period of 6 months. The results indicated that the losses of vitamin C were higher in the samples stored at 100°F. than in those stored at room temperature—regardless of the level of concentration. However, in the guava nectar the percentage of vitamin C destruction was relatively higher at lower concentrations and lower at higher concentrations at both temperatures. No such pattern could be observed in the juices. But the losses of vitamin C in the juices at all levels of concentration ranged below 30 percent at room temperature and below 40 percent at 100°F. This is relatively less than the losses that occurred in the guava nectar.

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