No abstract

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.

No abstract

905-906 (1961 ). 3 S. Hurwitt arid A. Appel, "Study of Phase Transformation With a Low Thermal Inertia High Temperature Diffractometer Attachnierit," Norrl,.o Kept., 8 [5] 90-91 (1961).

The volume compressibilities of BeO, ZnS, CdS, CdSe, and CdTe have been measured to 45 kbar. Solidsolid 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%.

No abstract

The crystal structure of fl-beryllia has been determined from X-ray powder data collected at 2100 °C The structure is tetragonal with a = 4.75 and c--2.74 A, and contains four molecules of BeO in the unit cell. The density is 2.69 g.cm -3. The structure is related to rutile, TiO~, in that the oxygen arrangement is identical. Beryllium atoms are in tetrahedral sites. The space group is P4~./mnm, and the oxygen and beryllium atoms are in sites 4(f) and 4(g) respectively with xo =0.310 and XBe --0"336.

No abstract