Premium
Use of monoatomic and polyatomic projectiles for the characterisation of polylactic acid by static secondary ion mass spectrometry
Author(s) -
Boschmans Bart,
Van Royen Pieter,
Van Vaeck Luc
Publication year - 2005
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2089
Subject(s) - polyatomic ion , chemistry , ion , mass spectrometry , monatomic ion , secondary ion mass spectrometry , analytical chemistry (journal) , yield (engineering) , projectile , static secondary ion mass spectrometry , atomic physics , materials science , organic chemistry , chromatography , physics , metallurgy
Abstract The application of polyatomic primary ions is a strongly developing branch of static secondary ion mass spectrometry (S‐SIMS), since these projectiles allow a significant increase in the secondary ion yields to be achieved. However, the different limitations and possibilities of certain polyatomic primary ions for use on specific functional classes of samples are still not completely known. This paper compares the use of monoatomic and polyatomic primary ions in S‐SIMS for thin layers of polylactic acid (PLA), obtained by spin‐coating solutions on silicon wafers. Bombardment with Ga + , Xe + and SF 5 +primary ions allowed the contribution of the projectile mass and number of atoms in the gain in ion yield and molecular specificity (relative importance of high m/z and low m/z signals) to be assessed. Samples obtained by spin‐coating solutions with increasing concentration showed that optimal layer thickness depended on the primary ion used. In comparison with the use of Ga + projectiles, the yield of structural ions increased by a factor of about 1.5 to 2 and by about 7 to 12 when Xe + and SF 5 +primary ion bombardment were applied, respectively. A detailed fragmentation pattern was elaborated to interpret ion signal intensity changes for different projectiles in terms of energy deposition and collective processes in the subsurface, and the internal energy of radical and even‐electron precursor ions. Copyright © 2005 John Wiley & Sons, Ltd.