Materials Literature
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The spectral distribution of the thermoluminescent glow peaks at 155, 206, and 333\ifmmode^\circ\else\textdegree\fi{}K and the room-temperature phosphorescence have been measured in Ca${\mathrm{F}}_{2}$: ${\mathrm{Ho}}^{+3}$ following x irradiation. The emission comprises about sixteen lines between 5300 and 5600 \AA{…
The metamagnetic (spin-flop) transition is studied in single crystals of Fe${\mathrm{Cl}}_{2}$ and Fe${\mathrm{Br}}_{2}$ using the M\"ossbauer effect and external magnetic fields up to 40 kG. From the changes which take place in the $m=\frac{1}{2}\ensuremath{\rightarrow}{m}^{*}=\frac{3}{2}$ and $m=\ensuremath{-}\frac{…
The ferroelectric properties of Rochelle salt have been studied by means of two new techniques based on the ${\mathrm{Na}}^{23}$ NMR. In the first technique, the separation between a pair of ${\mathrm{Na}}^{23}$ quadrupolar satellites is used as a measure of the spontaneous polarization of the crystal. Using this meth…
The velocity and attenuation of ultrasonic shear waves have been investigated at temperatures above ${T}_{C}={121.8}_{2}\ifmmode^\circ\else\textdegree\fi{}$K in single-crystal KDP. An elastic Curie-Weiss law, $({{s}_{66}}^{E}\ensuremath{-}{{s}_{66}}^{P})=\frac{D}{(T\ensuremath{-}{T}_{C})}$, is obtained with an elastic…
Neutron scattering from BaTi${\mathrm{O}}_{3}$ crystal has been investigated in the critical region (${T}_{c}=130\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}<T<270\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$) above the ferroelectric Curie temperature. In this temperature range, strong quasi-elastic scattering…
Using a vibrating-coil magnetometer, we have studied the effect of hydrostatic pressures of up to 11 kbar on the magnetic properties of MnAs. These experiments were carried out between 60 and 500\ifmmode^\circ\else\textdegree\fi{}K. The boundary between the ferromagnetic hexagonal ($B{8}_{1}$) phase and the orthorhomb…
The lattice-dynamical characteristic of the 110\ifmmode^\circ\else\textdegree\fi{}K transition in SrTi${\mathrm{O}}_{3}$ has been elucidated by inelastic neutron scattering measurements. The transition is caused by a ${\mathrm{T}}_{25}$ soft-phonon mode at the [111] zone boundary, confirming the model recently propose…
Energy spectra of electrons ejected from $M$ and $N$ subshells of krypton by characteristic x rays of 300 to 1500 eV energy have been measured with an electrostatic analyzer. Krypton was irradiated in the gas phase and electrons were detected perpendicular to the x-ray beam. From these spectra, relative subshell contr…
Abstract At least two distinct species, Proetus baylei n. sp., Nehou, Manche, France
The rate constants k1(sec.–1) for the thermal decompositions of cyclopentyl and cyclohexyl acetates in the presence of cyclohexene are 1012·89 exp (–44,110/RT) at 315–367° and 1012·59 exp (–45,190/RT) at 337–398° respectively. The decompositions are homogeneous and unimolecular in the seasoned Pyrex vessel. The relati…
A critical experiment is presented for the mechanisms of initiation and propagation of cleavage crack in iron. At first, precise fractographic observations are made on the type of the origin of crack observed on single crystals of iron with notch. A number of cleavage facets are started from the boundary of a twin, an…
Bu çalışma linear polarizasyon metodunun bu günkü durumunu ve bugüne kadar korozyon hızı tayinine uygulanmasını göstermektedir. Bu metodun çok pra¬tik ve faydalı olduğu gösterilmiştir. Metodun genel bir uygulama alanı göstermesi ve uygulanmasının kolay olması büyük bir avantaj sağlamaktadır. Bu metotla ko¬laylıkla kor…
A study was made on the quench sensitivity of Cu-0.3∼1.5%Cr alloys. The time-temperature-precipitation curve (T-T-P curve) was drawn by plotting the electrical conductivity of specimens which were solution treated and then directly quenched over the temperature range of isothermal heat treatment. The quench sensitivit…
Negative corona onset and sparkover voltages in air are shown to be affected by temperature, density, and the pipe-to-wire ratio of radii when using concentric cylindrical electrodes. Use of large wires at high temperatures demonstrates that onset of electrical discharge occurs at voltages significantly less than thos…
Abstract Screw, edge, and mixed dislocations are treated by a new method which is simple to handle. Labour saving equations are derived which further shorten the algebraic processes. The results emphasize the need for anisotropic expressions in the case of common cubic materials, and are presented in a form which show…
Abstract The effect of heavy doping on the reflection spectra of silicon and germanium is investigated by measuring the fractional change in reflectance, Δ R / R , between pure and doped materials. This effect arises from the narrowing of the forbidden gap in heavily doped materials. The form of the Δ R / R spectrum a…
Low-frequency i.r. and Raman spectra of InCl3,2Et2O, InBr3,2Et2O, InCl3,2Et2S, and InBr3,2Et2S are given and interpreted in terms of D3h skeletal symmetry.
Abstract Principal magnetic susceptibilities of single crystal of dysprosium ethylsulfate have been computed in the temperature range of liquid‐nitrogen to room temperature, assuming that the crystal field has C 3h symmetry around the Dy 3+ ion. It is observed that magnetic anisotropy increases with the decrease of te…
Abstract From temperature change experiments (between 260 and 435°C) during secondary creep of the intermetallic compound MgZn 2 an activation enthalpy Δ H = (2.25 ± 0.20) eV for basal slip has been derived. The shear strain rate γ can best be described by the empirical relation γ = 7 × 10 11 s −1 × τ 5.5 ± 1.0 exp (‐…
Abstract not Available.