2022
A N A L Y T I C A L CHEMISTRY
growths and poorly formed crystals of the pentahydrate. Plutonium tetranitrate pentahydrate, which is isomorphous with corresponding nitrates of thorium and cerium, is rather hygroscopic.
~~
Table I. Partial Powder X-Ray Diffraction Pattern d , A.. CJod. 7.24 5.645 5.364 4.995 4.764 3.965 3.888 3.822 3.820 3.400 3.306 3.175 3.1651 3.118 3.060 3.054) 2.972 2.823
hX1 111 040 131
220 022 240 151
~
0 I-
0
-
110
0
110;
202 222 311 113 331 242
ZGO OR2
133 171 080 400 3.51 420 153 202 004 313
Crystal of plutonium tetranitrate pentahydrate
O n b o g r e p b i c projection perallel to a and on (010)
~
Ib
~~
7.16 5.58
100 40 50
5.30 4.98 4.72
45 45
...
...
...
...
3.86 3.84
30 10
3.44 3.28 3.15 3.10 3.44 2.952
20 15
30
1ORPHOLOGY System and Class. Orthorhombic, pyramidal. Axial Elements. a:h:c = 0.493: 1:0.465 (derived from unit cell dimensions). Habit, Variable, equant or prismatic [OOl],flattened ( O l l l ) . Forms usually developed are (OlO), (1101, (1111, and (1111. Forg ( 011 1 is also frequently present, alone or accompanied by {all}. Interzonal Angles. (0111 A [OOl] = 65.0'; [loll A [OOl] = 46.7".
X-RAY DimnAmioN DATA Space Group. Fad2 ((2:). Cell Dimensions. a. = 11.14 f 0.02A.; bo = 22.58 i 0.03.4,; co = 10.51 i 0.03 A. Formula Units per Cell. 8; volume per formula unit 330.5 A.3 Formula Weight. 577.17. Density. 2.90 grams per cc. (x-ray); 2.896 (flotation).
.....
mediiim weak medium very weak weak weak 488, very strong 468, medium weak 447, medium strong
556, 548, 532, 516. 506.
Vibration,
Direation 2 650. strong 635. medium 620. medium 564, ,"&k ' . ,751;. medium wosk 54n. weak 535, medium weak 521, medium weak :OR, medium strong 4x8, "ery,stronC 477. medium strong
THERMAL DATA. On heating in air the crystals decompose slonly a t 70" C. to a viscous isotropic m a s , which a t slightly higher temperatures devitrifies to microcrystalline birefringent aggregates of another compound. Wona done under the auspieea of the Atomic Energy Commission. D a b ior gublioation in this section should be Sent t o Walter C. ,McCrone. 500 East 33rd St., Chicago 16, IU.
143. Cerium Tetranitrate Pentahydrate, Ce(N0,),m5H,0 EUGENE SIARITZKY, Tho University of California, Los Alamor Scientific Laboratory, Lo9 Alamos, N. M.
OPTICAL PROPERTIES Refractive Indices (5893 A.). nx = 1.554s; CY = 1.556; nz = 1.667; geometric mean 1.5916. Molecular refraction 67.41 CC. (based on measured density). Optic Orientation. X = h; Y = c; Z = a. Optic Axial Angle. ZVs(441 mp.) = 20'; 2Vz(470 mp.) = 17'; 2Vz(533 mp.) = 13'; 2Vz(589 mM.1 = 7.5O.
of cerium tetranitrate pentahydrate, isomorphous with corresponding compounds of thorium and plutonium, xere prepared by allowing a solution of ceric nitrate in couoentrated nitric acid to evaporate a t 35' C.
Color. X Y = yellowish green, Z = green, The absorption spectrum as observed through a Zeiss prism microspectrometer eyepiece, 'is given in Table 11.
CRYSTAL MORPHOLOGY System and Class. Orthorhonlbic, yramidal (from isomorphism with corresponding compounds o&horium and plutonium).
-
c.
RYSTALS
V O L U M E 28, NO. 1 2 , D E C E M B E R 1 9 5 6
2023
.4xial Elements. a:b:c = 0.493:1:0.464 (derived from unit cell dimensions). Habit. Dipyramidal by equaldevelopment of (111)and ( 1171, usually with subordinate (010) and often with [ 110). No hemihedral development was noted.
X-RAYDIFFRACTION DATA Space Group. Fddd (Ci:). Cell Dimensions. a. = 11.17 h 0.03 A . ; bo = 22.68 =k 0.06 A , : co = 10.53 f 0.04 A. Formula Units per Cell. 8; volume per formula unit 333.5 .4.3 Formula Teight. 478.24. Density. 2.38 grams per cc. (x-ray); 2.403 (flotation).
144. 145. 146. 147.
Yttrium Sesquioxide, Y,O, Dysprosium Sesquioxide, Dy,O; Erbium Sesqeioxide, Er,O, Ytterbium Sesquioxide, Yb,O,
E U G E N E STARITZKY, The University of California, Los Alamor Scientific Laboratory, Los Alamos. N. M.
Partial Powder X-Ray Diffraction Pattern hkl
d , A., Calcd. 7 26 5 67 5.38 5.01
4.78 3.98 3.90 3 83 3 63 3.47 3 31 3.18 3.17 3.13
d , A., Obsd." 7.23 5.64 5.36 4.98 4.76 3.97 3.88 3.82 3.61 3 46 3 30
2.984 2,835 2,792 2 , 778 2.711 2.694'l 2.6911 2,632 2.538 2.528 2 503
2,420 2 411 2,394 2,388) 2 381 2.330 2 3281 2 279 2,262 2,246 2.226
HE
