Spin dynamics in annealed Mn-doped ZnO ceramic materials

摘要

Influence of annealing on the electron spin resonance (ESR) spectra of Zn_(1-x)Mn_xO:1 mol% Zn_3P_2 (x = 001 and 0.02) ceramics was systematically investigated. The samples were annealed at temperatures (T_(an)) between 200 and 1100 ℃ for 12 h. The ESR spectra revealed the three characteristic regions. In the first region (200 ≤ T_(an) ≤ 700 ℃), the ESR spectra exhibited a broad Lorentzian-type single line, and the ESR intensity decreased with increasing T_(an). In the second region (700 ≤ T_(an) < 1000 ℃), the ESR spectra appeared Mn~(2+) hyperfine lines within a broad Lorentzian single line, indicating that Mn~(2+) ions substituted into Zn~(2+) lattice sites. The signal intensity and number of Mn~(2+) hyperfine lines increased with increasing T_(an). In the third region (T_(an) ≥ 1000 ℃), the Mn~(2+) hyperfine lines became broadened and finally blurred into the background line, resulting in a strong increase in the ESR signal. The origins of the ESR spectra, in relation to their X-ray diffraction patterns, are elucidated.