Consequences of High Adatom Energy during Pulsed Laser Deposition of La_0.7Sr_0.3MnO₃

The impact of the adatom energy on the stoichiometry, surface morphology, and crystalline twinning during pulsed laser deposition of La_0.7Sr_0.3MnO₃ is studied. We show that although nonthermal growth using highly energetic adatoms results in very smooth ultrathin films, it also causes preferential resputtering of Mn and a surface roughening transition with increasing film thickness. This can be circumvented by carefully tuning the adatom energy into thermal growth, resulting in more Mn rich samples and a delayed roughening transition. Furthermore, we demonstrate that the crystalline twinning can be controlled by controlling the adatom energy. Hence, a detailed control of the adatom energy during growth opens for better stoichiometry control as well as surface quality