Electron spin resonance identification di-carbon-related centers in irradiated silicon.

A previously unreported electron spin resonance (ESR) spectrum was found in γ-ray irradiated silicon by the detection of the change in microwave photoconductivity arising from spin-dependent recombination (SDR). In the specially prepared silicon crystals doped by ¹³C isotope, a well resolved hyperfine structure of SDR-ESR lines due to the interaction between electrons and two equivalent carbon atoms having nuclear spin <italic>I </italic>=<italic></italic>1/2 was observed. The Si-KU4 spectrum is described by spin Hamiltonian for spin <italic>S </italic>=<italic></italic>1 and of <bold><italic>g</italic></bold> and <bold><italic>D</italic></bold> tensors of orthorhombic symmetry with principal values <italic>g</italic>₁ = 2.008, <italic>g</italic>₂ = 2.002, and <italic>g</italic>₃ =2.007; and <italic>D</italic>₁ = ± 103 MHz, <italic>D</italic>₂ = ∓170 MHz, and <italic>D</italic>₃ = ± 67 MHz where axes 1, 2, and 3 are parallel to the [ 1 1 ¯ 0 ], [110], and [001] crystal axes, respectively. The hyperfine splitting arising from ¹³C nuclei is about 0.35 mT. A possible microstructure of the detect leading to the Si-KU4 spectrum is discussed. [ABSTRACT FROM AUTHOR]