Synthesis and Properties of Ytterbium Doped C60

1994 ◽  
Vol 349 ◽  
Author(s):  
Stephen H Irons ◽  
P. Klavins ◽  
J.Z. Liu ◽  
M.D. Lan ◽  
R.N. Shelton ◽  
...  
Keyword(s):  
High Temperatures ◽  
Magnetic Relaxation ◽  
Liquid Ammonia ◽  
Stoichiometric Composition ◽  
Amorphous Structure ◽  
Precise Control ◽  
Relaxation Effects ◽  
Magnetization Data ◽  
Long Time

ABSTRACTYtterbium doped C60 (YbxC60) has been synthesized through the use of a liquid ammonia intercalation route. This allows for precise control of the stoichiometric composition. Magnetization data were taken in fields up to 1 Tesla and temperatures between 5 and 300 K on samples with 1≤X≤5. We find the ytterbium introduces significant anisotropies into the system which give rise to long time magnetic relaxation effects that persist to high temperatures. We suggest the existence of an amorphous structure to explain the results.

scholarly journals Long-Time Magnetic Relaxation in Antiferromagnetic Topological Material EuCd2As2

2021 ◽  
Vol 38 (7) ◽  
pp. 077201
Author(s):  
Yang Wang ◽  
Cong Li ◽  
Yong Li ◽  
Xuebo Zhou ◽  
Wei Wu ◽  
...  
Keyword(s):  
Magnetic Relaxation ◽  
Long Time

Application of ultrasound in the investigation of magnetic relaxation effects in a ferromagnet

1985 ◽  
Vol 48 (2) ◽  
pp. 245-248
Author(s):  
P. P. Galenko ◽  
V. I. Alekseenko
Keyword(s):  
Magnetic Relaxation ◽  
Relaxation Effects

Non-Stoichiometric Compounds Derived From Point Defects

1994 ◽  
Author(s):  
Koji Kosuge
Keyword(s):  
Point Defects ◽  
Stoichiometric Composition ◽  
Pressure Gauge ◽  
Chemical Properties ◽  
Phase Rule ◽  
Chemical Balance ◽  
Long Time ◽  
Oxygen Gas ◽  
Pump Pressure ◽  
The One

In this chapter, we discuss ‘classical’ non-stoichiometry derived from various kinds of point defects. To derive the phase rule, which is indispensable for the understanding of non-stoichiometry, the key points of thermodynamics are reviewed, and then the relationship between the phase rule, Gibbs’ free energy, and non-stoichiometry is discussed. The concentrations of point defects in thermal equilibrium for many types of defect structure are calculated by simple statistical thermodynamics. In Section 1.4 examples of non-stoichiometric compounds are shown referred to published papers. The technical term ‘non-stoichiometric compounds’ has been used for a long time, in contradiction to the term ‘stoichiometric compounds’. The existence of non-stoichiometric compounds, which have also been called Bertholides compounds, cannot be explained from the law of definite proportion in its simplest meaning. Proust insisted that only stoichiometric compounds (also named Daltonide compounds) existed, whereas Bertholet maintained the existence of not only stoichiometric compounds but also non-stoichiometric compounds. This is a very famous argument in the history of chemistry. In the early years of the twentieth century, Kurnakov investigated the physical and chemical properties of intermetallic compounds in detail and found that the maximum or minimum in melting point, electrical resistivity, and also in the ordering temperature of lattices does not necessarily appear at the stoichiometric composition. An important discovery of Dingman was that stoichiometric FeO1.00 is non-existent under ordinary conditions. (At present, we can synthesize stoichiometric FeO1.00 under high pressure.) Non-stoichiometry, which originates from various kinds of lattice defect, can be derived from the phase rule. As an introduction, let us consider a trial experiment to understand non-stoichiometry (this experiment is, in principle, analogous to the one described in Section 1.4.8). Figure 1.1 shows a reaction vessel equipped with a vacuum pump, pressure gauge for oxygen gas, pressure controller for oxygen gas, thermometer, and chemical balance. The temperature of the vessel is controlled by an outer-furnace and the vessel has a special window for in-situ X-ray diffraction. A quantity of metal powder is placed on the chemical balance, and then the vessel is evacuated at room temperature.

scholarly journals Synthesis of the Tetragonal Phase of Zintl’s NaTl and Its Structure Determination from Powder Diffraction Data

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1356 ◽  
Author(s):  
Susanne Tiefenthaler ◽  
Nikolaus Korber ◽  
Stefanie Gärtner
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Liquid Ammonia ◽  
Powder Diffraction Data ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Structure Solution ◽  
Long Time ◽  
Original Procedure ◽  
Model Independent

A tetragonal distortion of the long-time known NaTl structure at 298 K was observed in different experimental setups, including Zintl’s original procedure of reducing Tl(I)-iodide by sodium liquid ammonia solutions. The powder diffraction pattern obtained by the high temperature synthesis using classical solid-state techniques allowed a model-independent unambiguous structure solution and refinement of tetragonal distorted NaTl (Rp = 0.0179, wRp = 0.0246, R = 0.0477, wR = 0.0527, GooF = 1.24).

Origin of the Hydrogen Absorbed by Incoherent TiC Particles in Iron

2005 ◽  
Vol 475-479 ◽  
pp. 233-236 ◽  
Author(s):  
Kaneaki Tsuzaki ◽  
Fu Gao Wei
Keyword(s):  
Heat Treatment ◽  
Water Vapor ◽  
High Temperatures ◽  
Thermal Desorption ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Trap Hydrogen ◽  
Thermal Desorption Spectrometry ◽  
Long Time

Hydrogen absorption of incoherent TiC particles that were once reported to be strong hydrogen traps in iron at room temperature was investigated by means of thermal desorption spectrometry (TDS). The results indicated that incoherent TiC particles in iron do not trap hydrogen at all at room temperature even they are cathodically charged for a long time. Only at high temperatures and in atmosphere containing hydrogen source, incoherent TiC particles can trap hydrogen. The origin of hydrogen trapped by incoherent TiC particles was justified to be water vapor in the atmosphere during heat treatment.

Long‐time magnetic relaxation measurements on a quench melt growth YBCO superconductor

1994 ◽  
Vol 76 (10) ◽  
pp. 6950-6952 ◽  
Author(s):  
L. H. Bennett ◽  
L. J. Swartzendruber ◽  
M. J. Turchinskaya ◽  
J. E. Blendell ◽  
J. M. Habib ◽  
...  
Keyword(s):  
Magnetic Relaxation ◽  
Ybco Superconductor ◽  
Melt Growth ◽  
Relaxation Measurements ◽  
Long Time

The Effects of Microstructural Variations on Stress-Corrosion Cracking Susceptibility of Ti-8Al-1Mo-1V Alloy on Marinized Gas Turbines

1967 ◽  
Author(s):  
W. P. Danesi ◽  
R. A. Sprague ◽  
M. J. Donachie
Keyword(s):  
Titanium Alloys ◽  
Stress Corrosion ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Gas Turbines ◽  
Effective Means ◽  
Corrosion Cracking ◽  
Corrosion Testing ◽  
Time Operation ◽  
Long Time

Salt can cause titanium alloys to crack, and if long-time operation of titanium hardwares in salt atmospheres is expected, effective means must be found to eliminate or control this tendency. The authors describe in detail their stress-corrosion testing of titanium alloys, and the results are plotted in a number of tables. Figures show stress-versus-temperature charts at different high temperatures, and the microstructure of the alloy after testing is illustrated. The results of the tests are evaluated and a brief summary is given.

INVESTIGATION OF ROBOTIC BRACES OF PATIENTS WITH IDIOPATHIC SCOLIOSIS (IS) — REVIEW OF THE LITERATURE AND DESCRIPTION OF A NOVEL BRACE

2018 ◽  
Vol 18 (08) ◽  
pp. 1840038 ◽  
Author(s):  
XINJIAN NIU ◽  
CHIFU YANG ◽  
BOWEN TIAN ◽  
XIANG LI ◽  
SHUTAO ZHENG ◽  
...  
Keyword(s):  
Idiopathic Scoliosis ◽  
Maximal Exercise ◽  
Three Dimensional ◽  
Review Of The Literature ◽  
Precise Control ◽  
Skin Breakdown ◽  
Long Time ◽  
Point Pressure ◽  
Treatment Theory ◽  
Mechanism Theory

Idiopathic scoliosis (IS) is a complex three-dimensional (3D) deformity. The non-operative treatments for IS have been developed for a long time. According to current studies, hard braces are more effective than soft braces for the treatment of scoliosis. Though current braces are proved to be effective for the treatment of IS, there are several shortcomings needed to be overcome: (i) Braces cannot realize precise control over a specific vertebra. (ii) Braces affect cardiopulmonary efficiency (braces limit maximal exercise performance). (iii) The brace is not modulated based on user’s needs. (iv) Braces, including motions during eating, tying shoes, sitting, and standing. (v) Braces apply forces on skin, which causes pain, skin breakdown, and abnormal deformation of bone. In order to solve these boring problems of the current braces, this paper proposed a new intelligent robotic spine brace based on the principle of human biomechanics, three point pressure treatment theory and parallel mechanism theory. This novel brace can offer 3D active dynamic adjustable corrective forces for the treatment of IS and some experiments are employed for verifying the effect of the proposed brace.

Sign in / Sign up

Export Citation Format

Share Document