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Neptunium diarsenide and monoarsenide
INOliG.
NUCL.
CHEM. LETTERS
Vol. 9,
pp. 337-342,
1973. Pergamon Press.
Printed in
Great Britain.
N E P T U N I U M D I A R S E N I D E AND M O N O A R S E N I D E J.P.
C H A R V I L L A T and D. D A M I E N
D E P A R T E M E N T DE G E N I E R A D I O A C T I F S E R V I C E D ' H Y D R O M E T A L L U R G I E ET DE C H I M I E DES TRANSURANIENS
(Received 23 October 1972)
A s a p a r t of a s y s t e m a t i c e f f o r t to study the c r y s t a l c h e m i s t r y of the t r a n s u r a n i u m e l e m e n t c h a l c o g e n i d e s and p n i c t i d e s , we r e p o r t
in this
l e t t e r the p r e p a r a t i o n , c r y s t a l l o g r a p h i c c h a r a c t e r i z a t i o n a n d t h e r m a l s t a b i l i t y of N e p t u n i u m Diarsenicte and M o n o a r s e n i d e .
EXPERIMENTAL N e p t u n i u m D i a r s e n i d e w a s p r e p a r e d on a 100 m g s c a l e by v a p o u r p h a s e r e a c t i o n of an e x c e s s m e t a l l i c A r s e n i c on 2 3 7 N e p t u n i u m h y d r i d e As 4} The r e a c t i o n w a s c a r r i e d out in a p y r e x tube s e a l e d u n d e r Np .
fatom
high v a c u u m ( r e s i d u a l p r e s s u r e l e s s than 10 -5 m m Hg) and h e a t e d at 310, 330°C for a w e e k . A f t e r that t i m e the r e a c t i o n s e e m e d to be c o m p l e t e and a s a m p l e w a s t a k e n for X - R a y e x a m i n a t i o n . X - R a y s t u d i e s w e r e p e r f o r m e d in a 1 1 4 . 6 m m d i a m e t e r N o r e l c o P h i l i p s p o w d e r c a m e r a . The r e m a i n i n g p r o d u c t w a s p l a c e d in a r e c o r d i n g M e t t l e r T h e r m o a n a l y z e r for v a c u u m d e c o m p o s i t i o n s t u d i e s using A l u m i n i a c r u c i b l e s .
RESULTS
AND
DISCUSSIONS
D e s p i t e the e x c e s s A r s e n i c u s e d in o u r e x p e r i m e n t s , the h i g h e r N e p t u n i u m A r s e n i d e to be f o r m e d was the D i a r s e n i d e a s it a p p e a r e d f r o m X -Ray measurements.
337
338
NEPTUNIUM DIARSENIDE AND MONOARSENIDE
Vol. 9, No. 3
A l l the X - R a y d i f f r a c t i o n lines of this c o m p o u n d could be indexed in the q u a d r a t i c s y s t e m of FeZAs t y p e . The l a t t i c e p a r a m e t e r v a l u e s w e r e c a l c u l a t e d u s i n g the c o m p u t e r p r o g r a m m given in r e f e r e n c e (1). The obtained results were : a
=
3.962
+
0.001
~k
b
=
8. 115
+
0.002
~k
T a b l e I g i v e s the line l i s t and indexing f o r the X - R a y p o w d e r p a t t e r n , the o b s e r v e d and c a l c u l a t e d 2 ~ , a n d the o b s e r v e d and c a l c u l a t e d line i n t e n s i t i e s . The i n t e n s i t i e s c a l c u l a t i o n s w e r e p e r f o r m e d with a r e f i n e m e n t p r o g r a m m (2). The tempe~.ature and a b s o r p t i o n
factors were neglected.
E x a m i n a t i o n of U A s 2 (3) and NpAs 2 X - R a y p o w d e r data s u g g e s t s that t h e s e c o m p o u n d s a r e i s o s t r u c t u r a l and b e l o n g to the s p a t i a l g r o u p P 4 / n m m like T h A s Z (4). The l a t t i c e p a r a m e t e r s of T h o r i u m , U r a n i u m and N e p t u n i u m D i a r s e n i d e s a r e c o m p a r e d in T a b l e II.
A t t e m p t s w e r e m a d e to p r e p a r e a s i m i l a r 2 3 9 p l u t o n i u m c o m p o u n d u s i n g the e x p e r i m e n t a l p r o c e d u r e d e s c r i b e d a b o v e . Under t h e s e conditions the only P l u t o n i u m A r s e n i d e to be obtained was P u A s (5) a n d no A r s e n i c r i c h e r p h a s e could be d e t e c t e d .
The t h e r m o g r a v i c c u r v e showing the N p A s 2 t h e r m a l s t a b i l i t y a p p e a r s in F i g u r e 1. The f i r s t change in weight o c c u r i n g at 310°C was due to the v o l a t i l i z a t i o n of the A r s e n i c e x c e s s . N p A s 2 was found to be s t a b l e u n d e r high v a c u u m up to 600°C. At h i g h e r t e m p e r a t u r e d e c o m p o s i t i o n o c c u r e d and the obtained p r o d u c t was i d e n t i f i e d as N p A s by the c h a n g e in weight d e t e r m i n a tion and by X - R a y e x a m i n a t i o n .
No slope v a r i a t i o n could be o b s e r v e d on the t h e r m o g r a v i m e t r i c c u r v e s d u r i n g the t r a n s f o r m a t i o n NpAs2---> N p A s .
This s u g g e s t s the a b s e n c e of
any i n t e r m e d i a r y decomposition product.
N p A s was found to c r y s t a l l i z e in the cubic s y s t e m with the Na C1
Vol. 9, No. 3
NEPTUNIUM DIARSENIDE AND MONOARBEIqIDE
TABLE Np
h
1 2 3 4 5 6 7 8
002 011 II0 003 Iii I12 013 004 020 113 014 022 211 114 023 015 213 204
9 I0 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
k
/
1
b
2O 214 222 301 106 310 223 116 31~. 125 303 007 133
As 2
X
Ray
observed 2 ~
calculated 2 9"
21.90 25. O0 31.94 33.10 33.86 39.08 40.36 44.74 45.84 46.70 50.56 51,44 52.90 56.30 57.72 61.84 62.70 65.94
21.95 25.06 31.99 33.16 33.90 39.12 40.42 44.71 45.85 46.72 50.59 51.37 52.93 56.00 57.72 61.81 62.72 65.94
66.74 70.66 71.24 72.52 74.08 75.99 76.86 78.54
66.82 70.61 71.25 72.55 74.10 75.99 76.63 78.57 80.21 8O. 24 81.06 83.39 85.42
80.20
80.94 83.60 85.62
339
I data.
observed intensity W S M MW M S M T MS VW W W MW T M W M T
calculated intensity ~ 32.1 114.9 61.1 40.1 58.8 124.9
62.8
M W T VW W W
MW T MS T T T
t
6.4 63.5 12.3 12.2 14.4 32.2 0.1 33 13.9 35.3 8.3 18.1 Zl 9.3 5.7 6.6 16.6 10.8 14.5 2.4 32.3 13.5 8.8 2.1 2.4
T h e l i n e i n t e n s i t i e s o f t h e N p A s 2 X Ray. p o w d e r p a t t e r n w e r e c a l culated using the UAs Z atom parameters (6). 2 A s i n 0, 0, 0, 1 r , ~1, 0 % 2Asin 2 U
0, 1
x,
in 0, Z , Y,
b = broad line.
1
0, ~
~[ , 0 , , ~
w i t h x =-0. 359 withy
= 0.282
NEPTUNIUMDIABSBNIDEANDMONOARSENIDE
340
Vol. 9, No.3
! !
I I
t I
t t
I
I I
.m
|
t I I
3 mg
I I \
¢-
Expanded TG scale
¢lb t-
I ! t
o J~
| , L Np As~+As~(I)Np A s ~ ' ~
3 mg NpAs
I I I I t I
1
100
I
300
I
600
I
I
Temp.,
1200 °C
Fig. i
t y p e of s t r u c t u r e a n d w i t h l a t t i c e , p a r a m e t e r
a
= .~. 8 3 8 9
+ m
O. 0 0 0 3
.~
X - R a y d a t a a r e g i v e n in T a b l e I I I .
This value reported above was obtained with a NpAs single phase s a m p l e f o r m e d a t 640 °. A t 1Z00°C w e a k l i n e s c o r r e s p o n d i n g to N p O 2 w e r e o b s e r v e d in the X-l%ay p a t t e r n a n d t h e N p A s l a t t i c e p a r a m e t e r 5.8338
+
0. 000Z
A.
s h r i n k e d to
T h i s d e c r e a s e of t h e N p A s l a t t i c e p a r a m e t e r v a -
l u e in the p r e s e n c e o f N p O 2 s u g g e s t s t h e p o s s i b i l i t y of e x i s t e n c e of a s o l i d solution between these compounds.
ACKNOWLEDGMENTS T h e a u t h o r s t h a n k P . C h a r p i n a n d P . M e r i e l f o r t h e i r h e l p in u s i n g the intensities calculations programm.
Voi. 9, No. $
N~UM
DIAIWI~qlDEAND MONOAilSIm~IDE
TABLE Th,
U,
Np
Th
Diarsenide
II lattice
c
4. 086
8. 575
3.954
8.116 8 . 1 32 8. I15
3. 962 3.962
Np .
TABLE Np
h k 1 1
111
2 3
200 220 4 311 5 22 2 6 40 0 7 33 I 8 42 0 9:42 2 I0 511, 333 II 44 0 121 5 3 1 131 600 , 4 4 2 14 62 0
53 3 2 44 4 , 551 64 0 2 ~0b64 17
observed Z0 26.54 30.73
43.98 52.05 54.54
63.87 70.47
72.49 80.73 86.84 96.74 102.88 104.87 113.41 120.17 122.42 132.41 141.22 144.40 162.12.
b = broad line.
parameters.
a
U
As
X
~M.
Re,
4 4 7 This work.
IIl Ray
calculated 2~
26.61 30.79 44. Ol 52.09 54.59 63.90 70.41 72.51 80.73 86.84 96.75 102.82
104.87 113.32 120.02 122.35 132.39 141.13 144.42 162.25
data. observed intensity
calculated intensity~
M+ VS S M IV[+ M W MS MS W W MW M+ M T M T M M S
34.1 73.1 55.4 17.5 19.7 9.3 7.4
25.8 19.6 6.1 7.1 7.7 16.9 13.7 4.2 14.9 5.8 12.8 22.9 91.8
342
NEPTUNIUM DIARSENIDE AND MONOARSENIDE
Vol. 9, No. 3
REFERENCES (1) M. TOURNARIE J o u r n a l de Physique 30, 10, (1969) (2) P . b i E R I E L , F . ROCHE and J . RABOT P r i v a t e communication. (3) IANDELLI Atti. Accad. Noz. L i n c e i , Rend. , C l a s s e , Sc. 144 (1952).
F i s . , Mat. N a t . , 13,
(4) R . W . W Y C K O F F Crystal Structures, Second Edition, Interscience publishers, a division of J. Wiley and Sons, New-York, London, Sydney, p. 361. (5) A . E . GORUM Acta c r y s t . 10, 144, (1957)
(6) A. O L E S Journal de Physique 26, 561, (1965)
(7) R. FERRO Congr~s Int. Chim. p u r e App1. 16 P a r i s 1957, Mere. Sect. Chim. Minera. le 1958, p. 353.
NUCL.
CHEM. LETTERS
Vol. 9,
pp. 337-342,
1973. Pergamon Press.
Printed in
Great Britain.
N E P T U N I U M D I A R S E N I D E AND M O N O A R S E N I D E J.P.
C H A R V I L L A T and D. D A M I E N
D E P A R T E M E N T DE G E N I E R A D I O A C T I F S E R V I C E D ' H Y D R O M E T A L L U R G I E ET DE C H I M I E DES TRANSURANIENS
(Received 23 October 1972)
A s a p a r t of a s y s t e m a t i c e f f o r t to study the c r y s t a l c h e m i s t r y of the t r a n s u r a n i u m e l e m e n t c h a l c o g e n i d e s and p n i c t i d e s , we r e p o r t
in this
l e t t e r the p r e p a r a t i o n , c r y s t a l l o g r a p h i c c h a r a c t e r i z a t i o n a n d t h e r m a l s t a b i l i t y of N e p t u n i u m Diarsenicte and M o n o a r s e n i d e .
EXPERIMENTAL N e p t u n i u m D i a r s e n i d e w a s p r e p a r e d on a 100 m g s c a l e by v a p o u r p h a s e r e a c t i o n of an e x c e s s m e t a l l i c A r s e n i c on 2 3 7 N e p t u n i u m h y d r i d e As 4} The r e a c t i o n w a s c a r r i e d out in a p y r e x tube s e a l e d u n d e r Np .
fatom
high v a c u u m ( r e s i d u a l p r e s s u r e l e s s than 10 -5 m m Hg) and h e a t e d at 310, 330°C for a w e e k . A f t e r that t i m e the r e a c t i o n s e e m e d to be c o m p l e t e and a s a m p l e w a s t a k e n for X - R a y e x a m i n a t i o n . X - R a y s t u d i e s w e r e p e r f o r m e d in a 1 1 4 . 6 m m d i a m e t e r N o r e l c o P h i l i p s p o w d e r c a m e r a . The r e m a i n i n g p r o d u c t w a s p l a c e d in a r e c o r d i n g M e t t l e r T h e r m o a n a l y z e r for v a c u u m d e c o m p o s i t i o n s t u d i e s using A l u m i n i a c r u c i b l e s .
RESULTS
AND
DISCUSSIONS
D e s p i t e the e x c e s s A r s e n i c u s e d in o u r e x p e r i m e n t s , the h i g h e r N e p t u n i u m A r s e n i d e to be f o r m e d was the D i a r s e n i d e a s it a p p e a r e d f r o m X -Ray measurements.
337
338
NEPTUNIUM DIARSENIDE AND MONOARSENIDE
Vol. 9, No. 3
A l l the X - R a y d i f f r a c t i o n lines of this c o m p o u n d could be indexed in the q u a d r a t i c s y s t e m of FeZAs t y p e . The l a t t i c e p a r a m e t e r v a l u e s w e r e c a l c u l a t e d u s i n g the c o m p u t e r p r o g r a m m given in r e f e r e n c e (1). The obtained results were : a
=
3.962
+
0.001
~k
b
=
8. 115
+
0.002
~k
T a b l e I g i v e s the line l i s t and indexing f o r the X - R a y p o w d e r p a t t e r n , the o b s e r v e d and c a l c u l a t e d 2 ~ , a n d the o b s e r v e d and c a l c u l a t e d line i n t e n s i t i e s . The i n t e n s i t i e s c a l c u l a t i o n s w e r e p e r f o r m e d with a r e f i n e m e n t p r o g r a m m (2). The tempe~.ature and a b s o r p t i o n
factors were neglected.
E x a m i n a t i o n of U A s 2 (3) and NpAs 2 X - R a y p o w d e r data s u g g e s t s that t h e s e c o m p o u n d s a r e i s o s t r u c t u r a l and b e l o n g to the s p a t i a l g r o u p P 4 / n m m like T h A s Z (4). The l a t t i c e p a r a m e t e r s of T h o r i u m , U r a n i u m and N e p t u n i u m D i a r s e n i d e s a r e c o m p a r e d in T a b l e II.
A t t e m p t s w e r e m a d e to p r e p a r e a s i m i l a r 2 3 9 p l u t o n i u m c o m p o u n d u s i n g the e x p e r i m e n t a l p r o c e d u r e d e s c r i b e d a b o v e . Under t h e s e conditions the only P l u t o n i u m A r s e n i d e to be obtained was P u A s (5) a n d no A r s e n i c r i c h e r p h a s e could be d e t e c t e d .
The t h e r m o g r a v i c c u r v e showing the N p A s 2 t h e r m a l s t a b i l i t y a p p e a r s in F i g u r e 1. The f i r s t change in weight o c c u r i n g at 310°C was due to the v o l a t i l i z a t i o n of the A r s e n i c e x c e s s . N p A s 2 was found to be s t a b l e u n d e r high v a c u u m up to 600°C. At h i g h e r t e m p e r a t u r e d e c o m p o s i t i o n o c c u r e d and the obtained p r o d u c t was i d e n t i f i e d as N p A s by the c h a n g e in weight d e t e r m i n a tion and by X - R a y e x a m i n a t i o n .
No slope v a r i a t i o n could be o b s e r v e d on the t h e r m o g r a v i m e t r i c c u r v e s d u r i n g the t r a n s f o r m a t i o n NpAs2---> N p A s .
This s u g g e s t s the a b s e n c e of
any i n t e r m e d i a r y decomposition product.
N p A s was found to c r y s t a l l i z e in the cubic s y s t e m with the Na C1
Vol. 9, No. 3
NEPTUNIUM DIARSENIDE AND MONOARBEIqIDE
TABLE Np
h
1 2 3 4 5 6 7 8
002 011 II0 003 Iii I12 013 004 020 113 014 022 211 114 023 015 213 204
9 I0 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
k
/
1
b
2O 214 222 301 106 310 223 116 31~. 125 303 007 133
As 2
X
Ray
observed 2 ~
calculated 2 9"
21.90 25. O0 31.94 33.10 33.86 39.08 40.36 44.74 45.84 46.70 50.56 51,44 52.90 56.30 57.72 61.84 62.70 65.94
21.95 25.06 31.99 33.16 33.90 39.12 40.42 44.71 45.85 46.72 50.59 51.37 52.93 56.00 57.72 61.81 62.72 65.94
66.74 70.66 71.24 72.52 74.08 75.99 76.86 78.54
66.82 70.61 71.25 72.55 74.10 75.99 76.63 78.57 80.21 8O. 24 81.06 83.39 85.42
80.20
80.94 83.60 85.62
339
I data.
observed intensity W S M MW M S M T MS VW W W MW T M W M T
calculated intensity ~ 32.1 114.9 61.1 40.1 58.8 124.9
62.8
M W T VW W W
MW T MS T T T
t
6.4 63.5 12.3 12.2 14.4 32.2 0.1 33 13.9 35.3 8.3 18.1 Zl 9.3 5.7 6.6 16.6 10.8 14.5 2.4 32.3 13.5 8.8 2.1 2.4
T h e l i n e i n t e n s i t i e s o f t h e N p A s 2 X Ray. p o w d e r p a t t e r n w e r e c a l culated using the UAs Z atom parameters (6). 2 A s i n 0, 0, 0, 1 r , ~1, 0 % 2Asin 2 U
0, 1
x,
in 0, Z , Y,
b = broad line.
1
0, ~
~[ , 0 , , ~
w i t h x =-0. 359 withy
= 0.282
NEPTUNIUMDIABSBNIDEANDMONOARSENIDE
340
Vol. 9, No.3
! !
I I
t I
t t
I
I I
.m
|
t I I
3 mg
I I \
¢-
Expanded TG scale
¢lb t-
I ! t
o J~
| , L Np As~+As~(I)Np A s ~ ' ~
3 mg NpAs
I I I I t I
1
100
I
300
I
600
I
I
Temp.,
1200 °C
Fig. i
t y p e of s t r u c t u r e a n d w i t h l a t t i c e , p a r a m e t e r
a
= .~. 8 3 8 9
+ m
O. 0 0 0 3
.~
X - R a y d a t a a r e g i v e n in T a b l e I I I .
This value reported above was obtained with a NpAs single phase s a m p l e f o r m e d a t 640 °. A t 1Z00°C w e a k l i n e s c o r r e s p o n d i n g to N p O 2 w e r e o b s e r v e d in the X-l%ay p a t t e r n a n d t h e N p A s l a t t i c e p a r a m e t e r 5.8338
+
0. 000Z
A.
s h r i n k e d to
T h i s d e c r e a s e of t h e N p A s l a t t i c e p a r a m e t e r v a -
l u e in the p r e s e n c e o f N p O 2 s u g g e s t s t h e p o s s i b i l i t y of e x i s t e n c e of a s o l i d solution between these compounds.
ACKNOWLEDGMENTS T h e a u t h o r s t h a n k P . C h a r p i n a n d P . M e r i e l f o r t h e i r h e l p in u s i n g the intensities calculations programm.
Voi. 9, No. $
N~UM
DIAIWI~qlDEAND MONOAilSIm~IDE
TABLE Th,
U,
Np
Th
Diarsenide
II lattice
c
4. 086
8. 575
3.954
8.116 8 . 1 32 8. I15
3. 962 3.962
Np .
TABLE Np
h k 1 1
111
2 3
200 220 4 311 5 22 2 6 40 0 7 33 I 8 42 0 9:42 2 I0 511, 333 II 44 0 121 5 3 1 131 600 , 4 4 2 14 62 0
53 3 2 44 4 , 551 64 0 2 ~0b64 17
observed Z0 26.54 30.73
43.98 52.05 54.54
63.87 70.47
72.49 80.73 86.84 96.74 102.88 104.87 113.41 120.17 122.42 132.41 141.22 144.40 162.12.
b = broad line.
parameters.
a
U
As
X
~M.
Re,
4 4 7 This work.
IIl Ray
calculated 2~
26.61 30.79 44. Ol 52.09 54.59 63.90 70.41 72.51 80.73 86.84 96.75 102.82
104.87 113.32 120.02 122.35 132.39 141.13 144.42 162.25
data. observed intensity
calculated intensity~
M+ VS S M IV[+ M W MS MS W W MW M+ M T M T M M S
34.1 73.1 55.4 17.5 19.7 9.3 7.4
25.8 19.6 6.1 7.1 7.7 16.9 13.7 4.2 14.9 5.8 12.8 22.9 91.8
342
NEPTUNIUM DIARSENIDE AND MONOARSENIDE
Vol. 9, No. 3
REFERENCES (1) M. TOURNARIE J o u r n a l de Physique 30, 10, (1969) (2) P . b i E R I E L , F . ROCHE and J . RABOT P r i v a t e communication. (3) IANDELLI Atti. Accad. Noz. L i n c e i , Rend. , C l a s s e , Sc. 144 (1952).
F i s . , Mat. N a t . , 13,
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