Electron paramagnetic resonance ofZn1−xMnxOthin films and single crystals

Abstract

$X$-band electron paramagnetic resonance spectra were recorded for ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{O}$ films grown by pulsed laser deposition and a single crystal for comparison. For different Mn concentrations in ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{O}$ films we performed measurements in dependence on the angle between the applied magnetic field and the $c$ axis of the wurtzite ZnMnO lattice. The fine and hyperfine structure splitting parameters and $g$ values were determined by modeling the experimental spectra. For both single crystal and films the investigations showed the incorporation of Mn ions at Zn lattice sites as ${\mathrm{Mn}}^{2+}$. For higher Mn concentrations, a broad Lorentzian single line, probably due to divalent Mn ions in higher local concentrations undergoing exchange, was found superimposed onto the resolved ${\mathrm{Mn}}^{2+}$ spectrum at $g=2.000$. Furthermore, by extrapolating the lattice-distortion-dependent fine-structure parameters determined for samples with a Mn content of $x\ensuremath{\leqslant}0.035$, we anticipate that for ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{O}$ single crystals and thin films on $c$-plane sapphire with $x=0.045$ the $D$ fine-structure parameters should be equal.