Correlated substitution in paramagnetic Mn 2 + -doped ZnO epitaxial films

TLDR: Using x-ray absorption spectroscopy and magnetic circular dichroism, the authors found that Mn(II) was found to substitute for Zn(II), with only a paramagnetic dichroic component from the Mn and no magnetic component from either the O or Zn.

Abstract: Epitaxial films of ${\text{Mn}}^{2+}$-doped ZnO were deposited by pulsed laser deposition on $\ensuremath{\alpha}{\text{-Al}}_{2}{\text{O}}_{3}(0001)$ using targets created from ${\text{Mn}}^{2+}$-doped ZnO nanoparticles. Using x-ray absorption spectroscopy and x-ray magnetic circular dichroism, Mn(II) was found to substitute for Zn(II) in the w\"urtzite ZnO lattice with only a paramagnetic dichroic component from the Mn and no magnetic component from either the O or Zn. The dichroism reveals that, while substitutional, the ${\text{Mn}}^{2+}$ distribution in the ZnO lattice is not stochastic. Rather, ${\text{Mn}}^{2+}$ has a tendency to substitute with higher effective local concentrations than anticipated from a stochastic doping model.