Mass spectroscopic studies on the laser ablation of boron nitride

The laser ablation of pyrolytic boron nitride pBN.target was investigated by quadrupole mass spectroscopy. The laser-correlated ion mass spectra and time-of-flight TOF.spectra were obtained. Bqand Bq2 ions were detected but Nq, Nq2 , or BNq ions were not observable. Instead, neutral N2 molecules were detected. The velocity of Bq ions and temperature of the plume were derived by shifted Maxwell–Boltzmann fitting of the TOF spectra of Bq ions. At the laser fluence of 0.7 Jrcm2, the velocity of Bq ions was 21.7 kmrs and the temperature was 15 765 K. Also studied were the effects of the retarding field on the energetics of Bq ions. The space-charge effect was found to influence the dynamics of plume propagation significantly. The reactive laser ablation under N2 atmosphere has been attempted by using a pulsed valve synchronized with the laser pulse. q1998 Elsevier Science B.V.