X-ray Absorption and Emission Studies of Mn-doped ZnO Thin Films

Abstract

The electronic structure of Mn-doped ZnO thin films, a dilute magnetic semiconductor (DMS) having possible room temperature (RT) forromagnetism, synthesized with nominal compositions of Zn(1-x)Mn(x)O (x = 0.03, 0.05, 0.07, 0.10, and 0.15) by using the spray pyrolysis method are investigated using soft, X-ray absorption and emission spectroscopy. The intensity of the pre-edge spectral feature at the O K-edge increases with Mn concentration, which clearly reveals that there is a strong hybridization of Mn ions with the ZnO matrix. The near-edge X-ray absorption fine structure (NEXAFS) measurements at the Mn K- and L(3,2)-edges show a mixed valence nature for the Mn ions, with Mn(2+) and Mn(3+)/Mn(4+) states, and the Mn(3+)/Mn(4+) states are observed to increase with the Mn-concentration. Mn L(2,3) resonant inelastic X-ray scattering (RIXS) measurements show that the excess Mn interstitials appear in the sample and that direct exchange interactions with substitutional Mn atoms may explain the magnetic interaction in Mn-doped ZnO.