Preparation and Properties of Scandium Dihydride

摘要: Scandium dihydride was prepared and studied. outgassed at 800 deg C in a silica tube. The tube cooled to room temperature connected series of calibrated volumes containing purified hydrogen slightly below atmospheric pressure. Pressures were indicated on manometer read by cathetometer the nearest 0.05 mm Hg. metal heated slowly until reaction drop reading. At 450 observed, experiment held for 16 hr. promote any additional metal- reaction; none observed. this point, sufficient had reacted correspond ScH/sub 2.o//sub 27/. possibility considered that 3/, similar YH/sub might be formed lower temperatures. Two repetitions process yielded very little reaction. It is possible 3/ higher pressures. Vapor pressure data x-ray powder-diffraction are tabulated. lattice constant its standard deviation determined method Vogel Kempter, a/sub o/ = 4.78309 plus or minus 0.00047 A 25 ormore » C. Correcting refraction becomes 0/ 4.78315 A. For 4(ScH/sub 2/) per unit cell, theoretical density 2.851 g/cc, Sc-8H bond distance 2.0712 2/ may useful as high-temperature neutron moderator because it contains 7.31 x 10/sup 22/ atoms/cc. (B.O.G.)« less