MgO thin films with high optical transmittances (more than 90%) were prepared by cathodic vacuum arc deposition technique With the increase of arc current from 40 to 80 A the deposition pressure decreases and the film thickness Increases the atomic ratio of Mg/O in MgO thin films (obtained by RBS) increases from 097 to 117 giving that deposited at 50 A most close to the stoichiometric composition of the bulk MgO the grains of MgO thin films grow gradually as shown in SEM Images XRD patterns show that MgO (1 1 0) orientation is predominant for films prepared at the arc currents ranged from 50 to 70 A The MgO (1 0 0) orientation is much enhanced and comparable to that of MgO (1 1 0) for films prepared at the arc current of 80 A The secondary electron emission coefficient of MgO thin film Increases with arc current ranged from 50 to 70 A (C) 2010 Elsevier B V All rights reserved