Yields and mean free paths of photoelectrons from liquid hexamethyl phosphoric triamide

Journal Article · Mon Nov 01 04:00:00 EST 1982 · J. Chem. Phys.; (United States)

OSTI ID:6722545

Birkhoff, R D; Hubbell, Jr, H H; Ashley, J C; Painter, L R

Monochromatic photons between 775 and 500 A were incident almost normally (15/sup 0/) on the surface of liquid hexamethyl phosphoric triamide (HMPT). Incident and reflected beam strengths were measured with a double ion chamber filled with argon and the current leaving the cup of liquid was determined. After subtracting a portion of the current due to Ar/sup +/ drift into the cup, we obtained the photocurrent and, hence, the absolute photoemission yield. The yield falls from 9% at 16 eV to 5% at 25 eV. Such a falloff with increasing photon energy is expected from theory. The values are about double those calculated from theory using a three-step model for the photoemission and using the Born approximation to calculate electron mean free paths. Conversely, if the experimental yields are used in the three-step model, the electron mean free paths calculated from the data range from about 935 A at 16 eV to about 80 A at 24 eV and are about two to three times the theoretically predicted values.

• Research Organization: Health and Safety Research Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• OSTI ID: 6722545
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 77:9; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
AMIDES
ELECTROMAGNETIC RADIATION
EMISSION
FAR ULTRAVIOLET RADIATION
FLUIDS
LIGHT TRANSMISSION
LIQUIDS
MEAN FREE PATH
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOTOEMISSION
PHYSICAL PROPERTIES
RADIATIONS
REFLECTIVITY
SECONDARY EMISSION
SOLVENTS
SURFACE PROPERTIES
ULTRAVIOLET RADIATION