Analytical modeling of atomic-number-dependent electronic stopping cross sections in Si, C, 4H-SiC, Al, Ni, and Ag

Abstract Atomic number ( Z 1 ) dependencies of electronic stopping cross sections ( S e ) for channeling trajectories had been well explained for low-velocity ions; however, this is not the case with S e for random trajectories ( S e random ). We modeled the difference between the effective atomic number for random trajectories and that for channeling ones ( Z′ ) changing linearly with the difference between the actual atomic number and Z′ . The proportionality constant k for S e random in Al, Ni, and Ag for 1.8 × 10 8 cm s −1 ions was found to depend little on the target atomic number. k for S e random in 4H-SiC for 1.5 × 10 8 cm s −1 ions, on the other hand, located between k for S e random in Si for 1.5 × 10 8 cm s −1 ions and k determined from that for 1.4 × 10 8 cm s −1 ions in C and that for 2.0 × 10 8 cm s −1 ions in C.