Lithium nitride synthesized by in-situ lithium deposition and ion implantation for boron neutron capture therapy

Ishiyama, Shintaro; Baba, Yuji  ; Fujii, Ryo*; Nakamura, Masaru*; Imahori, Yoshio*

LiN synthesis on Li deposition layer was conducted without HO and O by in-situ lithium deposition in high vacuum chamber of 10 Pa and ion implantation techniques and the thermo-chemical stability of the LiN/Li/Cu tri-layered target for Boron Neutron Capture Therapy (BNCT) under laser heating and air exposure was characterized by X-ray photoelectron spectroscopy (XPS). Following conclusions were derived; (1) LiN/Li/Cu tri-layered target with very low oxide and carbon contamination was synthesized by in-situ lithium vacuum deposition and N ion implantation without HO and O additions, (2) The starting temperature of evaporation of LiN/Li/Cu tri-layered target increased by 120 K compared to that of the Li/Cu target and (3) Remarkable oxidation and carbon contamination were observed on the surface of LiN/Li/Cu after air exposure and these contaminated compositions was not removed by Ar heavy sputtering.