| Abstract
| - OH-, O-, and H- emissions from the [Ca24Al28O64]4+·4(OH-) (defined as C12A7-OH-) surface wereinvestigated by time-of-flight (TOF) spectrometry. The emission intensities were sensitive to surface temperatureand extraction field. The apparent activation energies of anions decreased with the increase of applied extractionfield. At an extraction field of 800 V/cm, the emission ratio of OH- to total anions is 0.98−0.65 in thetemperature range of 870−1075 K. The OH- emission from C12A7-OH- was described by the followingkinetic processes: the OH- anions in the cages migrated onto the sample surface by field enhanced thermaldiffusion, and then desorbed to form the gas-phase anions of OH-. The O- emission originated from thedissociation of O2- and OH-. Similarly, H- emission was also attributed to the dissociation of OH- on theC12A7-OH- surface.
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