Synthesis and characterization of LaB thin films on tungsten, rhenium, silicon and other substrates and their investigations as field emitters.

The paper deals with the comparative study of nanocrystalline Lanthanum hexaboride (LaB) thin films grown on various substrates by Pulsed laser deposition and Arc plasma method. Field emission studies were carried out on LaB films deposited on various substrates show metallic behavior of the emitters. The high value of field enhancement factors, indicating that the electron emission from LaB nanoscale protrusions deposited on emitter surface. The post field emission surface morphology of the emitters showed no significant erosion of the films during continuous operation. The observed behavior indicates that it is linked with the growth of LaB films on substrate crystal structure. The LaB nanocrystallites/nanowires films were synthesized using arc plasma method shows good emission current stability. The LaB micro/nanocrystallites were also obtained by picosecond laser irradiation which gives high enhancement β factor, and good emission current stability along with high current density. The results reveal that nanocrystalline LaB films, exhibit high resistance to ion bombardment and excellent structural stability and are more promising emitters for practical applications in field emission based new generation devices. [ABSTRACT FROM AUTHOR]