Electron collisions with trifluorides:BF_3 and PF_3 molecules

摘要

Absolute total cross sections (TCSs) for electron scattering from boron trifluoride (BF_3) and phosphorus trifluoride (PF_3) molecules have been measured using a linear transmission method.The electron energy ranges from 0.6 to 370 eV for BF_3 and from 0.5 to 370 eV for PF_3.The TCS energy dependence for BF_3 exhibits two very pronounced enhancements:resonantlike narrow feature located near 3.6 eV with the maximum value of 19.2X10~(-20) m~2,and intermediate energy very broad enhancement with two humps,one centered around 21 eV (18.8X10~(-20) m~2 in the maximum) and the other near 45 eV (19.5X10~(-20) m~2).For PF_3 the TCS has quite different low-energy dependence:at 0.5 eV it has a high value of 70X10~(20_ m~2 and decreases steeply towards higher energies.Beyond the minimum near 5.5 eV,the TCS reveals two distinct humps:the resonant one centered near 11 eV with the peak value of 32.9X10~(-20) m~2 and the second one much broader around 35 eV (27.9X10~(-20) m~2).The present TCSs for trifluorides are compared to each other as well as to previous TCS data for selected perfluorides and to results for their perhydrided counterparts.The differences and similarities in the shape and magnitude of TCSs are pointed out.