Stoichiometric controlling of boron carbide thin films by using boron-carbon dual-targets

Abstract

The stoichiometry of boron carbide thin films was controlled in the range of 0.1–8.9 via pulsed laser deposition by using boron-carbon dual-targets. The amorphous films sized 50 nm in thickness. The reaction rate of boron and carbon atoms increased with the increasing of target rotating speed. Carbon atoms preferentially substituted boron atoms within the chain site as sp2 hybridization at lower carbon concentrations and then within the icosahedrons site as sp3 hybridization at higher carbon concentrations.

Structural Evolution of B–C Thin Films Deposited from SPSed‐Target and Dual‐Target

“…Each endmember (chain end site) of the chain is bonded covalently to an atom along the equatorial girth (equatorial site) of three different icosahedra. Interpretation of Raman spectra, 15 structure data, 16 and Xray photoelectron spectra 17 are consistent with this model. Boron carbide exists as single-phase alloy ranging from the boron-rich side near 10 at.% carbon to carbon-saturated stoichiometry of about 20 at.% carbon.…”

“…A laser beam of the third harmonic (355 nm, 10 ns) of a Q-switched Nd: YAG laser (Quantel, Les Ulis, France) was introduced into the chamber. 17,22 III. Two kinds of targets were adopted as termed SPSed-target (B n C) and dual-target (B n C), respectively.…”

Stoichiometric controlling of boroncarbonitride thin films with using BN-C dual-targets

“…Therefore, atoms from starting materials should be easier to diffuse and react with each other in a thinner layer of atoms. 19 Further work has been carried out to study the nature of chemical environment of the prepared BCN films by XPS. After deconvolution and Shirley background fitting, the B 1s , C 1s and N 1s spectra were unsymmetrical and well fitted by the corresponding chemical environments base on former studies, 11 respectively (Fig.…”

“…The angle of incidence of the X-ray beam was fixed to 1 • . More details and the scheme of PLD equipment on the experimental can be found in our previous studies 11,19 and Fig. 1.…”

“…Unfortunately, the films were carbon poor, and carbon content was changed in a narrow range of 26.4∼32.8% caused by the composition limitation of the boron carbide starting material. Also in our previous works, [19][20][21] in the case of B x C y films, stoichiometric controlling for both elements in large scale have been done by using "smart" target, dual target.…”