IUPAC definition : The boundary between two phases. It is recommended that for the purpose of surface
analysis a distinction be made between 'surface' in general, 'physical surface' and
'experimental surface': Surface — The 'outer portion' of a sample of undefined depth;
to be used in general discussions of the outside regions of the sample. Physical Surface
— That atomic layer of a sample which, if the sample were placed in a vacuum, is the
layer 'in contact with' the vacuum; the outermost atomic layer of a sample. Experimental
Surface — That portion of the sample with which there is significant interaction with
the particles or radiation used for excitation. It is the volume of sample required
for analysis or the volume corresponding to the escape for the emitted radiation or
particle, whichever is larger.;
The boundary between two phases. It is recommended that for the purpose of surface
analysis a distinction be made between 'surface' in general, 'physical surface' and
'experimental surface': Surface — The 'outer portion' of a sample of undefined depth;
to be used in general discussions of the outside regions of the sample. Physical Surface
— That atomic layer of a sample which, if the sample were placed in a vacuum, is the
layer 'in contact with' the vacuum; the outermost atomic layer of a sample. Experimental
Surface — That portion of the sample with which there is significant interaction with
the particles or radiation used for excitation. It is the volume of sample required
for analysis or the volume corresponding to the escape for the emitted radiation or
particle, whichever is larger.