Effect of swift heavy ions irradiation on the migration behavior of strontium implanted into polycrystalline SiC

Abstract

The influence of swift heavy ions (SHIs) irradiation on the microstructure and the migration behavior of strontium (Sr) implanted into polycrystalline SiC were investigated using Rutherford backscattering spectrometry (RBS), Raman spectroscopy and scanning electron microscopy (SEM). The as-implanted and SHIs irradiated samples were vacuum annealed from 1100 to 1500 °C in steps of 100 °C for 5 h. Implantation of strontium (Sr) amorphized the SiC, while SHIs irradiation of the as-implanted SiC resulted in limited recrystallization of the initially amorphized SiC. Annealing at 1100 °C already caused recrystallization in both the irradiated and un-irradiated but implanted with Sr samples. At 1500 °C, a carbon layer appeared on the surface of the irradiated and un-irradiated but implanted with Sr samples. This was due to the decomposition of the SiC and subsequent sublimation of silicon leaving a free carbon layer on the surface. SHIs irradiation alone induced no change in the implanted Sr. Annealing the samples at 1400 °C caused a release of all implanted strontium in the SHIs irradiated samples, while 55% of implanted strontium was released in the un-irradiated but implanted with Sr samples. The enhanced Sr releasing in SHIs irradiated samples was explained in terms of the high number of pores in the irradiated samples compared to fewer pores in the un-irradiated but implanted with Sr samples. The results show that more Sr was released in the irradiated SiC samples.