Cobre

N A S A T E C H N I C A L TRANSLATION

NASA T T F-11,919

THE ELECTRICAL CONDUCTIVITY OF COPPER OXIDE

T r a n s l a t i o n of: "Zur Elektrischen L e i t f a h i g k e i r von K u p f e r - 0 xydu 1 " I n : Physik. Z. S o w j e t u n i o n , Vol. 2, p p . 4 5 3 - 4 6 7 , 1 9 3 2 .

I

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION OCTOBER 1968 WASHINGTON, D.C. 2 0 5 4 6

.

*NASA TT F-11,919

T H E ELECTRICAL CONDUCTIVITY O F C O P P E R O X I D E
V. P. Zhuze and B.'V.
ABSTRACT:

Kurchatov

The t e m p e r a t u r e dependency of e Z e c t r i e a 2 c o n d u c t i v i t y of c o p p e r o x i d e p Z a t e s w i t h different oxygen c o n t e n t s w i Z Z be i n v e s t i g a t e d . The e Z e c t r i c a Z c o n d u c t i v i t y of p u r e copper o x i d e at 1 2 O i s 2.7;10-" ohm-' c m The d i s s o c i a t i o n energy of t h e e Zectrons i n Cu20 amounts t o 0 . 7 2 u o Z t s . The e Z e c t r i c a Z c o n d u c t i v i t y of c o p p e r o x i d e i n c r e a s e s rapidZy w i t h t h e oxyge c o n t e n t ; t h e Z a t t e r i s n o t Zarger t h a n 0 . % o f t h e w e i g h t . The dissociation w o r k of e Z e c t r o n s i n weZZ-conductedt e s t s of c o p p e r o x i d e v a r i e s from 0 . 1 3 4 t o 0 . 1 2 9 v o Z t s .

.

E l e c t r i c a l p r o p e r t i e s of copper oxide i n r e c e n t t i m e s have /45354 f o r m e d t h e b a s i s o f a l a r g e number o f e x p e r i m e n t a l i n v e s t i g a t i o n s o w i n g t o t h e g r e a t t e c h n i c a l s i g n i f i c a n c e o f Cu20 a n d b e c a u s e it i s e a s y t o p r e p a r e copper o x i d e samples i n a c o n v e n i e n t form f o r experiment.
The p u b l i s h e d w o r k s e m p h a s i z e t h e e s s e n t i a l r o l e o f e x c e s s oxygen i n t h e e l e c t r i c a l c o n d u c t i v i t y o f c o p p e r o x i d e . Auwers a n d Kerschbaum [ l ] f o u n d a s i g n i f i c a n t d e c r e a s e i n e l e c t r i c a l co n d u c t i v i t y of copper oxide p l a t e s a f t e r h e a t i n g t h e l a t t e r f o r many h o u r s u n d e r h i g h v a c u u m or i n a n a t m o s p h e r e o f nitrogen. LeBlanc and Sachse [21 f u r t h e r i n v e s t i g a t e d t h e e l e c t r i c a l c o n d u c t i v i t y o f c o p p e r o x i d e power i n c o n n e c t i o n w i t h t h e w o r k i n g c o n d i t i on s which a l t e r e d t h e c o n t e n t of e x c e s s oxygen i n Cu20. The e l e c t r i c a l c o n d u c t i v i t y o f c o p p e r o x i d e powder h e a t e d i n vacuum i n w h i c h t h e r e were n o d e t e c t a b l e t r a c e s o f o x y g e n , /454 a m o u n t e d t o 10-9Q-1 cm-' a t 20° C a n d i n c r e a s e d t o 10-6f22-1c m - l , s i n c e t h e Cu20 i n t h e a i r a b so r b e d l e s s t h a n o n e p e r m i l o f o x y g e n T h e same a u t h o r r e a c h e d a s i m i l a r c o n c l u s i o n i n o t h e r e x p e r i m e n t s w i t h n i c k e l and c o b a l t oxide [ a ] . T h i s e x c e s s oxygen which t h e y g a v e t h e name " a c t i v e o x y g e n " , e x i s t s i n t h e o p i n i o n o f t h e a u t h o r i n a quasi dissolved state.They c o n s i d e r t h e p o s s i b i l i t y o f i t s e x i s t e n c e i n t h e form of c u p r i c oxide improbable, because it i s v e r y e a s y t o s e p a r a t e t h e oxygen f r o m c o p p e r o x i d e powder a t t e m p e r a t u r e s w h i c h c o r r e s p o n d t o a n i n s u f f i c i e n t Cu20 d i s s o c i a t i o n w o r k a c c o r d i n g t o the equation

9:Numbersi n t h e margin i n d i c a t e p a g i n a t i o n i n t h e f o r e i g n t e x t .

2cuo = cu20 t 0 Dubar 1 4 1 o b t a i n e d s i m i l a r r e s u l t s i n i n v e s t i g a t i o n o f c o p p e r o x i d e p l a t e s , i n which h e changed t h e c o n d i t i o n s of t h e t h e r m a l treatment. A thorough i n v e s t i g a t i o n of t h e s e c o n d i t i o n s which w a s...