Carl F. Cline

Elastic Constants of Hexagonal BeO, ZnS, and CdSe

The elastic moduli of hexagonal beryllium oxide, zinc sulfide, and cadmium selenide at 25°C have been determined by measuring ultrasonic wave velocities in the 20‐ to 50‐MHz frequency range. The data are compared with other literature data and discrepancies are discussed. The adiabatic bulk modulus, volume compressibility, and Debye temperatures are also computed.

Volume Compressibility of BeO and Other II‐VI Compounds

The volume compressibilities of BeO, ZnS, CdS, CdSe, and CdTe have been measured to 45 kbar. Solid‐solid transitions were observed in CdS, CdSe, and CdTe at 17.5, 21.3, and 31.8 kbar, respectively, with corresponding volume changes of 16.0%, 16.4%, and 16.4%.

The effects of neutron irradiation on a superconducting metallic glass

The effects of fast neutron irradiation on a superconducting metallic glass (Mo /sub 6/Ru /sub 4/)/sub 82/B/sub 18/ have been studied. Following irradiation to a total fluence of 10/sup 19/ n/cm/sup 2/, T/sub c/ increases from 6.05 K to 6.19 K, and the width of the transition decreases sharply. The density of the material decreases by 1.5%, and the x-ray scattering intensity maxima are broadened. An improvement in the ductility of the samples is observed which together with the other observations suggests the production of defects having atomic scale dimensions and characterized by excess volume.

Measurements of the electronic and nuclear contributions to the nonlinear refractive index of beryllium fluoride glasses

The nonlinear refractive‐index coefficient n2 of three beryllium fluoride glasses was measured at 1064 nm using time‐resolved interferometry. The refractive‐index nonlinearity of amorphous BeF2 is the smallest reported for any solid. From Raman scattering spectra, the nuclear contribution n2 was found to be ≈20–30% of the total, a factor similar to that for oxide glasses.

Electrical Transport Processes in Beryllium Oxide

The electrical resistivity was determined for polycrystalline and single‐crystal BeO between 1200°–1700°C. Analysis was made of the effects of oxygen partial pressure, aliovalent impurities, and microstructure. Conductivity and relevant diffusion coefficients were calculated with these data. The results show the BeO samples to be impurity‐controlled ionic conductors, and establish the need for higher‐purity material to study intrinsic properties. Electrical migration is independent of grain boundaries and crystallographic direction. Creation of cation defects by varying the oxygen activity in the specimens is not an important process in this material. At high temperatures, above a critical roll‐over temperature determined by the impurity content, electrical transport processes occur by a vacancy mechanism with an activation energy of 65 ± 5 kcal/mole. At lower temperatures, the electrical transport process is more complex and no simple theory is applicable. It is suggested that precipitation of impurities...

X-ray Data for the Chrome-Urania System, Cr2O3·2UO3

A NEW binary compound in the chrome-urania system has been briefly described by Borchardt1. This compound has been prepared by mechanically mixing 78 weight per cent uranium oxide (UO2) and 22 weight per cent chromium oxide (Cr2O3), pressing the mixture into pellets and firing to 1,250° C. in platinum dishes. The samples were reground and refired and then examined by chemical, optical, and X-ray techniques. A trace of free chrome was observed optically in mixtures where the chemical analysis indicated excess chromium over a Cr: U atom ratio of 1. The X-ray powder patterns indicated only one phase.

STIMULATION OF THERMOLUMINESCENCE IN LiF BY RUBY LASER LIGHT

Single crystals of LiF, fractured internally at liquid nitrogen temperature by a focused 30‐nsec pulse from a ruby laser, showed thermoluminescence peaks at 100° and 140°K. Reddish coloration at the damage centers annealed out at 550°C. Analog of the glow peaks with those reported for LiF subjected to x rays and gamma rays and attributed to release of self‐trapped electrons with subsequent transitions and recombinations, suggests that the ruby laser pulse can ionize electrons in LiF, possibly by multiple photon processes or through the medium of defect species.

X-ray Data for the Chrome-Urania System, Cr2O3|[middot]|2UO3

A NEW binary compound in the chrome-urania system has been briefly described by Borchardt1. This compound has been prepared by mechanically mixing 78 weight per cent uranium oxide (UO2) and 22 weight per cent chromium oxide (Cr2O3), pressing the mixture into pellets and firing to 1,250° C. in platinum dishes. The samples were reground and refired and then examined by chemical, optical, and X-ray techniques. A trace of free chrome was observed optically in mixtures where the chemical analysis indicated excess chromium over a Cr: U atom ratio of 1. The X-ray powder patterns indicated only one phase.

X-RAY DATA FOR THE CHROME-URANIA SYSTEM, Cr

A NEW binary compound in the chrome-urania system has been briefly described by Borchardt1. This compound has been prepared by mechanically mixing 78 weight per cent uranium oxide (UO2) and 22 weight per cent chromium oxide (Cr2O3), pressing the mixture into pellets and firing to 1,250° C. in platinum dishes. The samples were reground and refired and then examined by chemical, optical, and X-ray techniques. A trace of free chrome was observed optically in mixtures where the chemical analysis indicated excess chromium over a Cr: U atom ratio of 1. The X-ray powder patterns indicated only one phase.