Enhanced Mechanical Properties of LaF₃ Thin Films by Ion Plating Deposition

Abstract

The mechanical properties of lanthanum fluoride (LaF₃) films are investigated. The films are deposited by using a resistive heating (RH) boat evaporation method and the advanced ion plating (AIP) method. A severe abrasion resistance test and a laser induced damage threshold (LIDT) test are done on the films. Abrasion resistance is increased by increasing the deposition temperatures for RH films. On the other hand, for AIP films, abrasion resistance is increased by adding direct current (DC) bias voltage. It is confirmed that the AIP films have a superior LIDT characteristics than those of RH films. With an additional DC bias voltage superimposed to a self bias voltage, the abrasion resistance and LIDT value is further improved. Based on the proposed mechanism of LIDT process, the microstructures of LaF₃ films are discussed.