Page 21 - Academic Press Encyclopedia of Physical Science and Technology 3rd InOrganic Chemistry

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Encyclopedia of Physical Science and Technology EN001F-11 May 7, 2001 12:19

Actinide Elements 229

TABLE XI Binary Actinide Oxides a
Lattice parameters
Compound Color Symmetry b a( ˚ A) b ( ˚ A) c ( ˚ A) α (deg) β (deg) γ (deg)

Ac 2 O 3 White Hexagonal 4.07 6.29
ThO 2 White Cubic 5.5971
Pa 2 O 5 White fcc 5.446
Pa 2 O 5 White Tetragonal 5.429 5.503
Pa 2 O 5 White Hexagonal 3.817 13.220
Pa 2 O 5 White Rhombohedral 5.424 89.76
Pa 2 O 5 White Orthorhombic 6.92 4.02 4.18
PaO 2.42 -PaO 2.44 White Rhombohedral 5.449 89.65
PaO 2.40 -PaO 2.42 White Tetragonal 5.480 5.416
PaO 2.33 White Tetragonal 5.425 5.568
PaO 2.18 -PaO 2.21 White fcc 5.473
PaO 2 Black fcc (CaF 2 ) 5.509
α-U 3 O 8 Dark green Orthorhombic 6.716 11.960 4.147
β-U 3 O 8 Dark green Orthorhombic 7.069 11.445 8.303
α-U 2 O 5 Black Monoclinic 12.40 5.074 6.75 99.2
β-U 2 O 5 Black Hexagonal 3.813 13.18
γ -U 2 O 5 Black Monoclinic 5.410 5.481 5.410 90.49
α-UO 3 Beige Orthorhombic 6.84 43.45 4.157
β-UO 3 Orange Monoclinic 10.34 14.33 3.910 99.03
γ -UO 3 Yellow Orthorhombic 9.813 19.93 9.711
δ-UO 3 Deep red Cubic 4.16
ε-UO 3 Brick red Triclinic 4.002 3.841 4.165 98.10 90.20 120.17
Brown Orthorhombic 7.511 5.466 5.224
η-UO 3
UO 2 Dark brown fcc 5.704
Np 2 O 5 Dark brown Monoclinic 4.183 6.584 4.086 90.32
NpO 2 Brown-green Cubic 5.425
α-Pu 2 O 3 Black bcc 11.04
β-Pu 2 O 3 Black Hexagonal 3.841 5.958
PuO 2 Yellow fcc 5.3960
A-Am 2 O 3 Red-brown Hexagonal 3.817 5.96
B-Am 2 O 3 Red-brown Monoclinic 14.38 3.52 8.92 100.4
C-Am 2 O 3 Cubic 11.03
AmO 2 Dark brown fcc 5.374
A-Cm 2 O 3 White Hexagonal 3.792 5.985
B-Cm 2 O 3 White Monoclinic 14.282 3.641 8.883 100.29
C-Cm 2 O 3 White Cubic 11.002
CmO 2 Black Cubic 5.3584
A-Bk 2 O 3 Yellow-green Hexagonal 3.754 5.958
C-Bk 2 O 3 Yellow-green bcc 10.887
BkO 2 Brown fcc 5.3315
A-Cf 2 O 3 Pale green Hexagonal 3.72 5.69
B-Cf 2 O 3 Pale green Monoclinic 14.124 3.591 8.809 100.31
C-Cf 2 O 3 Pale green bcc 10.839
CfO 2 Black fcc 5.310
Black bcc 10.766
Es 2 O 3
Es 2 O 3 Monoclinic 14.1 3.59 8.80 100
Es 2 O 3 Hexagonal 3.7 6.0
a The most stable oxide of each element is italicized. Where more than one modification exists, the first listed is
italicized.
b bcc, body-centered cubic; fcc, face-centered cubic.