Angle- and time-resolved mass spectrometric study on pulsed laser ablationof 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 wi th 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 a re mainly formed via a nonthermal process, while the neutral atoms mainly v ia a thermal one. The angular distributions of Mn+ ions and Mr; atoms can b e described by a cos(n)theta and a bicosine function acos theta + (1 - a)co s(n)theta, respectively. Possible mechanisms of laser ablation of La-Ca-Mn- O are discussed.