Local environment of a diluted element under high pressure: Zn1−xMnxO probed by fluorescence x-ray absorption spectroscopy

Abstract

The authors report on x-ray absorption measurements performed on Zn1-xMnxO x=0.05, 0.25 at the Mn K edge 6539 eV under high pressure. Mn is found to substitute for Zn both in the low pressure wurtzite phase and in the high pressure rocksalt phase. The Mn–O bond length is determined to be 2.02±0.01 Å at ambient conditions, with a compressibility similar to that of Zn–O in pure ZnO, being dictated by the ZnO crystalline environment. The phase transition is reversible in Zn0.95Mn0.05O, but not in Zn0.75Mn0.25O. The authors demonstrate that fluorescence detected x-ray absorption under high pressure can be used to characterize structural changes around minority elements

X-ray absorption study of the local order around Mn in Mn:ZnO thin films: the role of vacancies and structural distortions

“…On the other hand, as shown inFig. 8, there are there are some differences between the XANES spectra of these samples and that reported by Pellicer et al [25]. The Mn K-edge XANES spectra of both Ar-Zn 0.95 Mn 0.05 O and Ar/N 2 -Zn 0.95 Mn 0.05 O samples shows a decrease of the white-line intensity and a well defined peak at ∼ 16 eV above the edge.…”

“…This peak is not present in the spectrum reported in Ref. [25] nor in the theoretical calculation. The comparison of the experimental spectra with that of MnO 2 suggests that this peak is simply due to the presence of a small amount of MnO 2 in the samples, also in agreement with the white line reduction due to the diverse Mn environments.…”

“…1. They are compared to the Mn K-edge spectra recorded for a Zn 0.95 Mn 0.05 O thin film by Pellicer-Porres et al [25] and to the theoretical computations performed by Yan et al [13].…”

“…The theoretical spectra have been compared to the experimental spectra reported by Pellicer et al [25]. As shown in Fig.…”

The phase transition of Zn0.854Cu0.146O under high pressure

“…A phase transition from B4 to cubic rocksalt (B1) structure (space group Fm3m) occurs at high pressure above 9.0 GPa with an increased coordination number from 4 to 6 [7]. This high-pressure phase transition has been widely investigated using energy dispersive X-ray diffraction [8][9][10], X-rayabsorption near-edge structure [11], Raman scattering [12], and photoluminescence measurements [13]. Recently, highpressure induced phase transition from wurtzite to rocksalt phases has also been observed in ZnO nanocrystals [14,15].…”