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First-principles study of the Na(110) surface
A48 Surface Science 209 (1989) 455-464 North-Holland, Amsterdam
455
N M R S T U D Y OF THICK FILMS OF M E T H A N E O N GRAPHITE M.S. PETTERSEN * and D.L. G O O D S T E I N California Institute of Technology, Pasadena, CA 91125, USA Received 22 June 1988; accepted for publication 17 October 1988 We report the results of an N M R survey of the system methane adsorbed on graphite near the triple point temperature, in the thick-film regime (10-50 layers) where the methane behavior is substantially bulk-like. We study the interaction of the film with the substrate and find that T l is affected by a dipolar coupling with paramagnetic spin centers in the substrate. Since the systematics of these effects are now understood, they can be used as diagnostics in their own right. We are able to conclude that solid methane wets the graphite basal plane substrate to a thickness of at least 50 layers in the temperature range 70 K < T < 105 K. On the Grafoil substrate we employ, such thick films ought to be unstable with respect to capillary condensation, but capillary condensation is evidently not nucleated in our experiments.
Surface Science 209 (1989) 465-480 North-Holland, Amsterdam
465
ENERGY L O S S OF E L E C T R O N S TRAVELLING T H R O U G H CYLINDRICAL HOLES N. ZABALA, A. R I V A C O B A and P.M. E C H E N I Q U E Departamento Fisica de Materiales, Facultad de Qulmica, Euskal Herriko Unibertsitatea, Aptdo. 1072, San Sebastian 20080, Spain Received 28 June 1988; accepted for publication 20 October 1988
Expressions for the energy loss due to interaction with surfaces experienced by fast electrons passing through holes drilled in a coated medium are derived within the framework of the classical dielectric theory. These expressions are evaluated for Al coated with alumina using experimental values of the dielectric constant c(~0) of the different media. Retarded energy loss probabilities are derived and some applications are discussed. Deflection effects due to the image force acting on the particle are also analysed.
Surface Science 209 (1989) 481-491 North-Holland, Amsterdam
FIRST-PRINCIPLES S T U D Y OF THE Na(110) SURFACE T. R O D A C H , K.-P. B O H N E N Kernforschungszentrum Karlsruhe, Institut fiir Nukleare FestkSrperphysik, P.O. Box 3640, D-7500 Karlsruhe, Fed. Rep. of Germany
and
481
455
N M R S T U D Y OF THICK FILMS OF M E T H A N E O N GRAPHITE M.S. PETTERSEN * and D.L. G O O D S T E I N California Institute of Technology, Pasadena, CA 91125, USA Received 22 June 1988; accepted for publication 17 October 1988 We report the results of an N M R survey of the system methane adsorbed on graphite near the triple point temperature, in the thick-film regime (10-50 layers) where the methane behavior is substantially bulk-like. We study the interaction of the film with the substrate and find that T l is affected by a dipolar coupling with paramagnetic spin centers in the substrate. Since the systematics of these effects are now understood, they can be used as diagnostics in their own right. We are able to conclude that solid methane wets the graphite basal plane substrate to a thickness of at least 50 layers in the temperature range 70 K < T < 105 K. On the Grafoil substrate we employ, such thick films ought to be unstable with respect to capillary condensation, but capillary condensation is evidently not nucleated in our experiments.
Surface Science 209 (1989) 465-480 North-Holland, Amsterdam
465
ENERGY L O S S OF E L E C T R O N S TRAVELLING T H R O U G H CYLINDRICAL HOLES N. ZABALA, A. R I V A C O B A and P.M. E C H E N I Q U E Departamento Fisica de Materiales, Facultad de Qulmica, Euskal Herriko Unibertsitatea, Aptdo. 1072, San Sebastian 20080, Spain Received 28 June 1988; accepted for publication 20 October 1988
Expressions for the energy loss due to interaction with surfaces experienced by fast electrons passing through holes drilled in a coated medium are derived within the framework of the classical dielectric theory. These expressions are evaluated for Al coated with alumina using experimental values of the dielectric constant c(~0) of the different media. Retarded energy loss probabilities are derived and some applications are discussed. Deflection effects due to the image force acting on the particle are also analysed.
Surface Science 209 (1989) 481-491 North-Holland, Amsterdam
FIRST-PRINCIPLES S T U D Y OF THE Na(110) SURFACE T. R O D A C H , K.-P. B O H N E N Kernforschungszentrum Karlsruhe, Institut fiir Nukleare FestkSrperphysik, P.O. Box 3640, D-7500 Karlsruhe, Fed. Rep. of Germany
and
481