Kinetics of solid-state reactions between zirconium thin film and silicon carbide at elevated temperatures

Abstract

Solid state reactions between a thin film (133 nm) of Zr and bulk single crystalline 6H-SiC substrates have been studied at temperatures between 600 °C and 850 °C for durations of 30, 60 and 120 min under high vacuum conditions. The deposited film and reaction zones were investigated by Rutherford backscattering spectrometry (RBS) and X-ray diffraction. The RBS spectra were simulated in order to obtain the deposited layer thickness, reaction zone compositions and reaction zone thickness. The as-deposited spectra fit well with those annealed at 600 °C, thus showing there were no reactions taking place. At temperatures of 700 °C and above, Zr reacted with the SiC substrate and formed a mixed layer of Zr carbide (ZrC x ) and Zr silicides (ZrSi, Zr 2 Si and Zr 5 Si 3 ). Annealing at 850 °C for 240 min revealed that all the deposited Zr had completely reacted. The interface reaction follows the parabolic growth law thereby indicating diffusion controlled reaction kinetics. The activation energy for the diffusion process obtained was 1.6 eV in the relatively narrow temperature range 700-850 °C.

Effect of hafnium contaminant present in zirconium targets on sputter deposited ZrN thin films

“…In this context, studies show a recurring content of hafnium in Zr and ZrN thin films deposited by RMS [9,10]. Due to the very low contamination (Hf < 1 at.%), detection of this chemical element is imperceptible by traditional characterization techniques, as EPMA [11] and EDS [12].…”

Interfacial reactions and surface analysis of W thin film on 6H-SiC

“…Interaction of palladium (Pd) with SiC has been investigated and was found to enhance the migration of silver [6][7][8][9]. The interaction between high yield FP such as zirconium (Zr) and SiC has also been reported [10,11].…”

The effect of thermal annealing in a hydrogen atmosphere on tungsten deposited on 6HSiC

“…There are several factors which may contribute to the failure of the SiC in retaining radioactive FPs. These include; thinning of the SiC layer due to reactions with FPs such as palladium (Pa) and zirconium (Zr) and the gas build up leading to a rise in pressure that may exerts strong tensile stress in the SiC and lead to cracks through which the FPs can escape [7][8][9][10][11].…”