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Interaction between phosphorus and oxygen on the Fe(111) surface
A401 A. M E I S E L
Karl-Marx-Universitiit Leipzig, Sektion Chemie, Talstrasse 35, Leipzig, DDR-7010, German Dem. Rep. Received 28 March 1987; accepted for publication 19 May 1987
The interaction between phosphorus segregated on the Fe(ll 1) surface and adsorbed oxygen was studied by means of AES, XPS, and LEED. The oxidative properties of two-dimensionally chemisorbed phosphorus layers produced by segregation and the interaction between the adsorbed oxygen and the Fe~P layer formed by segregation of oversaturated states were investigated. In the case of small degrees of surface coverage by phosphorus we propose a model to explain the experimental results. The adsorbed oxygen atoms can deposit themselves on the sites of phosphorus defects. This process displaces the phosphorus atoms into lower but still near-surface layers and results in the formation of F e - O compounds and P~ clusters. At temperatures of about 420 K F e - P - O species are formed. When heated to 700 K F e - P - O is decomposed and the initial state of oxygen is regained by oxygen diffusion into the bulk.
Surface Science 189/190 (1987) 199-203 North-Holland, Amsterdam HIGH
RESOLUTION
ELECTRON ENERGY O N Ge(100)
199 LOSS
STUDY
OF WATER A D S O R P T I O N L. P A P A G N O
*
Dipartimento di Energetica, Universitgt dell'Aquila, Monteluco, L'Aquila, Italy L.S. C A P U T I
*
Dipartimento di Fisica, Unwersitgl della Calabria, 87036 Arcavacata di Rende, Cosenza, Italy D. F R A N K E L ,
Y. C H E N
a n d G.J. L A P E Y R E
Department of Physics, Montana State University, Bozeman, M T 59717, USA Received 13 April 1987; accepted for publication 16 April 1987 The interaction of water with Ge(100) has been studied by high resolution electron energy loss spectroscopy (HREELS). Contrary to the silicon case, water does not stick on Ge(100) at room temperature at least for exposures as high as 100 langmuirs. When the sample is taken to 100 K, both molecular and dissociated water are present even for 0.1 L exposure. After heating the water exposed sample to 300 K only OH and H modes are present, suggesting a complete water dissociation.
Karl-Marx-Universitiit Leipzig, Sektion Chemie, Talstrasse 35, Leipzig, DDR-7010, German Dem. Rep. Received 28 March 1987; accepted for publication 19 May 1987
The interaction between phosphorus segregated on the Fe(ll 1) surface and adsorbed oxygen was studied by means of AES, XPS, and LEED. The oxidative properties of two-dimensionally chemisorbed phosphorus layers produced by segregation and the interaction between the adsorbed oxygen and the Fe~P layer formed by segregation of oversaturated states were investigated. In the case of small degrees of surface coverage by phosphorus we propose a model to explain the experimental results. The adsorbed oxygen atoms can deposit themselves on the sites of phosphorus defects. This process displaces the phosphorus atoms into lower but still near-surface layers and results in the formation of F e - O compounds and P~ clusters. At temperatures of about 420 K F e - P - O species are formed. When heated to 700 K F e - P - O is decomposed and the initial state of oxygen is regained by oxygen diffusion into the bulk.
Surface Science 189/190 (1987) 199-203 North-Holland, Amsterdam HIGH
RESOLUTION
ELECTRON ENERGY O N Ge(100)
199 LOSS
STUDY
OF WATER A D S O R P T I O N L. P A P A G N O
*
Dipartimento di Energetica, Universitgt dell'Aquila, Monteluco, L'Aquila, Italy L.S. C A P U T I
*
Dipartimento di Fisica, Unwersitgl della Calabria, 87036 Arcavacata di Rende, Cosenza, Italy D. F R A N K E L ,
Y. C H E N
a n d G.J. L A P E Y R E
Department of Physics, Montana State University, Bozeman, M T 59717, USA Received 13 April 1987; accepted for publication 16 April 1987 The interaction of water with Ge(100) has been studied by high resolution electron energy loss spectroscopy (HREELS). Contrary to the silicon case, water does not stick on Ge(100) at room temperature at least for exposures as high as 100 langmuirs. When the sample is taken to 100 K, both molecular and dissociated water are present even for 0.1 L exposure. After heating the water exposed sample to 300 K only OH and H modes are present, suggesting a complete water dissociation.