Dielectric Loss in Li- and Na-Swept α-Quartz and the Effect of Irradiation

1983 ◽  
Vol 24 ◽  
Author(s):  
J. Toulouse ◽  
A.S. Nowick
Keyword(s):  
Dielectric Loss ◽  
Low Temperature ◽  
Low Temperatures ◽  
Quantum Effects ◽  
Frequency Stability ◽  
Distorted Tetrahedron ◽  
High Quality ◽  
Quartz Crystals ◽  
Alkali Ions ◽  
Synthetic Crystals

ABSTRACTAlkali ions, which compensate for substitional Al3+, play an important role in the frequency stability of α-quartz crystals. In this work, low temperature dielectricloss measurements (between 2.9 and 300 K) are carried out on crystals that have been “swept” so as to introduce either Li+ or Na+. High quality synthetic crystals as well as natural crystals are employed. The well known loss peaks due to Al-Na pairs are further explored and similar peaks due to Al-Li are sought after but not found. It is concluded that the Al-Li pair is oriented along the C2 -axis of the A104 distorted tetrahedron. After irradiation, large peaks are observed at very low temperatures both in Li+- and Na+-containing crystals. These peaks, which are distorted below ∼6 K due to the onset of quantum effects, may originate in alkali centers produced when alkali ions are liberated by the irradiation.

Low-temperature Preparation of Crystallized Zirconia Films by ECR Plasma MOCVD

2005 ◽  
Vol 890 ◽  
Author(s):  
Hiroshi Masumoto ◽  
Takashi Goto
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Low Temperatures ◽  
Monoclinic Zirconia ◽  
High Quality ◽  
Ion Chamber ◽  
Ecr Plasma ◽  
Low Temperature Preparation ◽  
Oxide Ion ◽  
Zirconia Films

ABSTRACTIt is known that zirconia has excellent thermal and chemical stability, and oxide ion conduction. Therefore, YSZ is expected to be used as oxide ion conducting materials, optical mirror materials, catalytic materials and heat-resistant materials. Zirconia films have been fabricated by PVD (ex. sputtering and laser-ablation), chemical vapor deposition (CVD) and sol-gel methods. CVD is capable to prepare high quality zirconia films with excellent conformal coverage; however, deposition temperature of conventional CVD was usually high than PVD. On the other hand, an electron cyclotron resonance (ECR) plasma is high-activity plasma and high quality crystalline films can be obtained at low temperature by using ECR plasma. In the present study, zirconia thin films were prepared at low temperatures on quartz, polycarbonate and polyimide substrates by ECR plasma MOCVD.Zr-hexafluoroacetylacetonato solution was used as a precursor. The source, which was placed in a glass bubbler, was carried into a reactor by Ar gas. A microwave (2.45 GHz, 500 W) was introduced into the ion chamber through a rectangular wave guide. A magnetic field (875 Gauss) was applied to the ion chamber to satisfy the ECR condition. A mirror-type magnetic field (450 Gauss at the substrate stage) was applied in order to raise a plasma density, which results in an increase of the deposition rates of films. Substrate temperature (Ts) was from 30 to 700 C by water-cooling holder and infrared lamp heater. Microwave power was changed from 0 to 900 W. The deposition time was from 30 to 120 minutes.Cubic, monoclinic and tetragonal zirconia films were obtained over Ts=400 C, and cubic and monoclinic zirconia films were obtained below Ts= C. Cubic and monoclinic zirconia films were also obtained at no heating. The deposition rate increased from 10 to 20 nm/min with increasing Ts from no heating to 600 C. Crystallized zirconia films were obtained on polycarbonate and polyimide substrates at no heating. The ECR plasma was significantly effective to prepare crystallized zirconia films at low temperatures.

The ferromagnetic domain structure of haematite

1968 ◽  
Vol 303 (1475) ◽  
pp. 525-529 ◽  
Keyword(s):  
Low Temperature ◽  
Single Crystals ◽  
Domain Structure ◽  
Low Temperatures ◽  
Remanent Magnetization ◽  
Temperature Transition ◽  
Small Temperature ◽  
Temperature Range ◽  
Ferromagnetic Domain ◽  
Synthetic Crystals

Observations are reported of the ferromagnetic domain structure of natural and synthetic single crystals, made at temperatures close to the low temperature transition with the aid of an acetone based magnetic colloid. The domain structure of the synthetic crystals was found to change radically over a small temperature range centred around –12 °C. These changes are correlated with the measured remanent magnetization. Fairly extensive colloid patterns were found on the natural crystals at low temperatures but when the natural crystals were annealed at 1200 °C this low temperature colloid structure was no longer found.

scholarly journals Electron-enriched thione enables strong Pb–S interaction for stabilizing high quality CsPbI3 perovskite films with low-temperature processing

2020 ◽  
Vol 11 (12) ◽  
pp. 3132-3140 ◽  
Author(s):  
Xiaojia Xu ◽  
Hao Zhang ◽  
Erpeng Li ◽  
Pengbin Ru ◽  
Han Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Low Temperatures ◽  
High Quality ◽  
Low Temperature Processing

A neutral molecular additive of 4(1H)-pyridinethione (4-PT) is used for growing high quality black-phase CsPbI3 thin films at low temperatures.

Anomalies in the temperature dependence of the yield stress of metals at low temperatures

1983 ◽  
Vol 61 (11) ◽  
pp. 1528-1530 ◽  
Author(s):  
S. M. Raza
Keyword(s):  
Low Temperature ◽  
Temperature Dependence ◽  
Yield Stress ◽  
Low Temperatures ◽  
Structural Changes ◽  
Zero Point ◽  
Quantum Effects ◽  
Enhancement Effect ◽  
Polycrystalline Nickel ◽  
Creep Equation

Yield stress "anomalies" have been studied in polycrystalline nickel at low temperatures. Both quantum effects and structural changes below 0.1–0.2 of the Debye temperature contribute to low-temperature anomalies in the temperature dependence of the yield stress. The anomalies appear to be basically a consequence of the effect of zero-point vibrations on the rates of transition in the localized process of activation. An attempt is made to explain the anomalies by introducing a "strain-enhancement" effect, i.e., f(T), semiempirically in the logrithmic creep equation [Formula: see text] where Teff = T0 + AT2 (T0 and A are constants), which allows for quantum effects below a certain temperature.

High speed growth of MAPbBr3 single crystals via low-temperature inverting solubility: enhancement of mobility and trap density for photodetector applications

Nanoscale ◽  
2021 ◽  
Author(s):  
Yunae Cho ◽  
Hye Ri Jung ◽  
Yeon Soo Kim ◽  
Yejin Kim ◽  
Joohee Park ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Low Temperatures ◽  
High Speed ◽  
Single Crystal Growth ◽  
Complete Dissolution ◽  
High Quality ◽  
Optoelectronic Application ◽  
Hybrid Perovskite ◽  
First Time

High-quality CH3NH3PbBr3 hybrid perovskite single crystal growth and outstanding optoelectronic application using the complete dissolution at low temperatures based on low temperature solubility, which has been demonstrated for the first time.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

INVAR M93

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Low Temperatures ◽  
Bend Strength ◽  
Temperature Performance ◽  
Ni Content ◽  
Precision Alloys ◽  
Ni Alloy

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.

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