Conduction-electron spin resonance in zinc-blende GaN thin films

We report electron-spin-resonance measurements on zinc-blende GaN. The observed resonance has an isotropic g value of 1.9533±{}0.0008 independent of temperature, a Lorentzian line shape, and a linewidth (18 G at 10 K) which depends on temperature. The spin-lattice relaxation time at 10 K was estimated to be T₁ₑ=(6±{}2)×{}10^-5 sec. Using a five-band model a g value consistent with the experimental results was obtained and a conduction-electron effective mass m*/m₀=0.15±{}0.01 was calculated. The observed signal, together with conductivity data, was attributed to nonlocalized electrons in a band of autodoping centers and in the conduction band.