REPORT
t i o n of s u r f a c e s e g r e g a t i o n b y A u ger emission c a n t h r o w l i g h t . on w h a t h a p p e n s a t t h e inaccessible grain boundaries. Another app r o a c h is t o e x a m i n e i n t e r g r a n u l a r f r a c t u r e s u r f a c e s for c o n c e n t r a t i o n s of different species. A u g e r a n a l y s i s h a s also b e e n used for s u c h d i v e r s e p u r p o s e s as i d e n t i fication of c o a t i n g s on b e a r i n g surfaces, d e t e c t i o n of c a r b o n e v a p o r a t i o n from a t h o r i u m d i s p e n s e r c a t h ode, d e t e r m i n a t i o n of p o l a r i t y of S i C c r y s t a l s , a n d m e a s u r e m e n t of differences in m e r c u r y c o n t e n t of v a r i o u s l a m p electrodes.
For
VUV-UVVisible Spectroscopy 500Å to 6000Å
Ή6/ιώ cuwwml 'mnnmm
Future of the Method
ACûnninn Momyiikuymum υ π Α ΟΌ ν3 MjtfjWj matim tkot wwJm nw&oûjod)î& (wcwwiM... (mhmMjC/ T h e M c P h e r s o n M o d e l 225 f e a t u r e s a m a t h e m a t i c a l l y e x a c t c a m profile i n c o r p o r a t e d w i t h i n a u n i q u e , pat e n t e d * optical m e c h a n i c a l a r r a n g e m e n t t h a t p r o d u c e s a c c u r a t e focus at all w a v e l e n g t h s . . . a u t o m a t i c a l l y . . . c o n s i s t e n t l y . K i n e m a t i c a l l y m o u n t e d gratings are easily i n t e r c h a n g e d . S m a l l ID angle (15°], fixed focus for b o t h e n t r a n c e a n d exit slits, plus s t a t i o n a r y en t r a n c e a n d exit b e a m s c o m b i n e to h e l p m a k e t h e o n e m e t e r M o d e l 225 the s t a n d a r d for fast, a c c u r a t e a n d d e p e n d a b l e o p e r a t i o n the w o r l d over. N o w , for in c r e a s e d r e s o l u t i o n a n d d i s p e r s i o n select a 2 or 3 m e t e r Version.
«Patent No. 3,090,863
T h e M o d e l 225 is a c o n s i s t e n t p e r f o r m e r w i t h u n d i s p u t e d s u c c e s s in v a c u u m ultraviolet s p e c t r o s c o p y . W i t h the M c P h e r s o n d o u b l e b e a m a t t a c h m e n t , y o u r s p e c t r o s c o p y capability c a n b e b r o a d e n e d to i n c l u d e liquid or gas a b s o r p t i o n s t u d i e s , reflectance a n d t r a n s m i s s i o n s t u d i e s at r e d u c e d a n d e l e v a t e d tem p e r a t u r e s ; m a n y from w a v e l e n g t h s as l o w as 500Â u p to 6000Â. In short, w h e t h e r it's u s e d in single or d o u b l e b e a m m o d e , the 225 is an ideal i n s t r u m e n t for chemists, bio-chemists, metallurgists, physicists, ast r o n o m e r s , space scientists or e d u c a t o r s . M c P h e r s o n offers a complete line of precision i n s t r u m e n t s for a c c u r a t e analysis of the spectral range from soft X-ray to n e a r I.R. For further information on the M o d e l 225 N o r m a ] I n c i d e n c e S c a n n i n g M o n o c h r o mator, write or call:
Mc Pherson
INSTRUMENT CORPORATION
530C Main Street, Acton, Massachusetts 01720 · Telephone 617-263-7733 Circle No. 134 on Readers' Service Card
34 A
•
ANALYTICAL CHEMISTRY
I n s u m m a r y , A u g e r a n a l y s i s is a n o n d e s t r u c t i v e tool for i d e n t i f y i n g e x t r e m e l y s m a l l q u a n t i t i e s of s u r face c o n s t i t u e n t s . I t is a m e t h o d t h a t can be a p p l i e d a l m o s t as a r o u tine laboratory technique because t h e e q u i p m e n t a n d v a c u u m conditions required are modest. Although Auger analysis has been used p r i m a r i l y as a q u a l i t a t i v e a n a l y t i c a l m e t h o d , its usefulness will be g r e a t l y e n h a n c e d w h e n it can b e e x t e n d e d t o q u a n t i t a t i v e d e t e r m i n a t i o n s a n d , hopefully, will tell us s o m e t h i n g of t h e c h e m i c a l s t a t e s of t h e a t o m s d e t e c t e d . T h e r e is no d o u b t t h a t t h e i m p o r t a n t comb i n a t i o n of A u g e r a n d L E E D t e c h n i q u e s will do m u c h t o p r o v i d e t h e solid q u a n t i t a t i v e understanding n e c e s s a r y for t h e s e e n d s .
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Literature Cited (1) "Low Energy Electron Diffraction," in ANAL. CHEM,, 39, (4), 26A (1967).
(2) R. H. Millier, ibid., 40, (IS), 119A (1968); 40, (14), 81A (1968). (3) J. J. Lander, Phys. Rev., 91, 1382 (1953). (4) P. Auger, J. Phys. Radium, 6, 205 (1925). (5) E. H. S. Burhop, "The Auger Effect and Other Radiationless Transitions," University Press, Cambridge, England, 1952. (6) G. A. Harrower, Phys. Rev., 102,, 340 (1956). (7) K. Siegbahn et al. "Atomic, Molecular, and Solid State Structure Studied by Means of Electron Spectroscopy," Almquist and Wiksalls Boktryckeri AB, Uppsala, 1967. (8) L. A. Harris, J. Appl. Phys., 39, 1419 1(1968). (9) P. Palmberg and T. N. Rodin, ibid., T) 2425
(10) R. É. Weber and W. T. Peria, ibid., 38,4355 (1967). (11) L. A. Harris, ibid., 39, 1419 (1968).
