Angle- and time-resolved mass spectrometric study on pulsed laser ablation of an La-Ca-Mn-O target

Pulsed laser ablation (PLA) of an La₂O₃-CaO-MnO₂ target at 532 nm has been investigated by angle- and time-resolved quadrupole mass spectrometry. The results show that different kinds of metal oxides as well as metal ions and atoms are produced during the ablation at high laser fluence. The measured TOF spectra are fitted by multicomponent Maxwell-Boltzmann distribution with a stream velocity, which gives the translational energy of 6.34 and 0.43 eV for Mn⁺ ions and Mn atoms, respectively. It implies that ablated ions are mainly formed via a nonthermal process, while the neutral atoms mainly via a thermal one. The angular distributions of Mn + ions and Mn atoms can be described by a cos ⁿ θ and a bicosine function a cosθ+ (1-a)cos ⁿ θ, respectively. Possible mechanisms of laser ablation of La-Ca-Mn-0 are discussed. Project supported by the National Natural Science Foundation of China (Grant No. 29683001).