the “Coordination of Analytical Techniques in Industrial Research.” The properties and behavior of materials depend very largely on their chemical constitution and physical structure. In a research organization, and in technical industry generally, it is therefore of paramount importance to have available the proper facilities for determining the composition, structure, and other attributes of
153. R.
all materials of interest. I n fact, modern industry relies a t almost every stage of research, development, and production on the results of what has veen called broadly chemical analysis of materials used in, or in conjunction with, the product. I t is non- becoming more widely appreciated that “chemical analysis” goes further than determining the percentage composition of a sample, usually expressed in some rather arbitrary way. It refers to
Uranium Tetrabromide, UBr,
M. D0UGLASS:and EUGENE STARITZKY,
tetrabromide C were p r qofm cdui.aniuni by J . F. Suttle of the RI-STAIS
University of S e n - Mexico and this 1:horatoi.y by reaction of uranium dim i d e n-ith a tenfold excess of carbon tetrabromide at 175” C. and subliming off of the uianiuni tetrabromide thus EorIned. Quantitative chemical analysis gave, by n cight. 43.57% uranium and 56.107, bromine. to be cornpared with 42.69 and 57.317& rrspecstivelg. cnlcukited for ITBri. ( ‘RYSTAL
all those techniques and investigations which contribute to our knowledge of the structure and composition of materials. This conception of analysis implies t h a t the analyst may find himself as a individualina teamof 3 ecialists, someof whom would have no pface in the traditional chemistry laboratory. This in turn creates a situation in which some over-all coordination of the various analytical techniques is established and maintained.
~IORPHOLOGY
System. Monoclinic. Habit. -Elongated parallel to b, with { 1011, I l O l ] , and i O l l ) . Cleavage. (001} prominent.
S-n.4~ DIFFRACTION D.4~~4 Diffraction Symbol. 2/niC-/-. Cell Dimensions. a0 = 10.92 zk 0.02 -4., bo = 8.69 3~ 0.036k., co = 7.05 f 0.01 il., b’ = 93.9 f 0.1 : cell volume 667 k 3 ; o : b : c = 1.26:1:0.81. Formula Weights per Cell. 4 Formula Weight. 557.73. Density. 5.55 grams per cc. (calculated; weight of unit atomic \?-eight 1.6602 X gram): 5 35 [measured (I)].
Absorption Spectrum
Band mduina i n millimicrons and relative Intensities as viened n i t h Zeiss prism miciospectrometei eyepiece Parallel to x ti85 m ti70 VB
645 m
ti00 m, wide 583 vw 563 w 526 w 512 s
Parallel to 1.
Parallel to
z
665 vs, wide /675 vs 1660 s, wide
626 ms 600 vw 560 w
523 w
632 w 598 mw 558 vw 523 m 512 w 495 mw
The Universify o f California, Los Alamos Scientific loborofory, los Alamos, N.
M.
OPTICALPROPERTIES Refractive Indices (5893 A4.).n . ~= 1.86, n y = 2.02, n z = 2.06; geometric mean 1.98. Lorentz-Lorenz refraction 49.6 cc. Optic Orientation. Z = b ; X d c = sinail. OpticoAxial Angle (5893 A , ) . 2T’x = 51zk3. Color. Brovm.
Partial Powder X-Ray Diffraction Pattern of Uranium Tetrabromide
hkl
001 200 111 20i 020 02 1 229 202 22 1 311 202 130 022 4oi 312 312 420 33g 113 402 132 203 113 331 331 402 041 023 511 240 5ll 422 223
d, A , Calcd 7 03 5 45 4 78 4 45 4 35 3 io 3 40 3 05 3 01 2 95 2 87 2 80 2 73 2 60 2 51 2 35 2 31 2 26 2 25 2 23 2 211 2 21
2 129
d, A , Obsd a 6 99 5 48 4 77 4 48 4 36 3 70 3 41 3 Ob 3 02 2 96 2 86 2 82 2 75 2 60 2 51 2 36 2 32 2 28 2 25
Ill+ 10 3 2 3 7
1
2-
I
6
I
:3
6
