Manganese / zinc ratio influence on the thermal oxide nanostructure in the Mn-Zn-O system

Abstract

In this work, a facile method for targeted modification of oxidic surfaces is presented. A Mn thickness gradient film superimposed on a homogenous Zn layer was successfully prepared using the thermal co-evaporation technique. Heat treatment of the sandwich structure leads to oxide formation, whereas, the composition and structure of the resulting oxides is a function of the overlying Mn-film thickness. Studies of morphology, composition, topography and surface potential of the metallic as well as of the oxide film have been performed. All results show a strongly dependent correlation to the thickness of the Mn film. Two main nanostructures of the oxide film were obtained -nanoneedles and nanowalls. Based on these findings, oxide growth mechanisms are proposed. Thus, it is possible to create a certain composition and structure of an oxide solely by applying a distinct amount of the upper metallic layer. The most important specific oxides formed were Mn 3 O 4 , ZnMn 2 O 4 , MnO, and ZnO. Regarding the energy storage, these materials are important for further development and capability improvement of these devices.

Structural, Electrical, and Optical Effects of Metal Doping on ZnO Thin Films

“…Beside crystallography, important structural information about the crystallite size and lattice parameters can be calculated from XRD patterns. Using Debye‐Scherrer Equation , the crystallite size (D) of pristine and doped‐ZnO was calculated (Table ), with the exception of the Mn:ZnO for which the main peak lacks the symmetry characteristic to a single phase as already mentioned before, as well as W:ZnO that shows no peaks at all where k is the shape factor taken as 0.9, λ is the wavelength of the x‐ray radiation, β is the full width at half maximum (FWHM) of the peak and θ is the diffraction angle.…”

“…The strongest influence on the crystallinity of the ZnO film is achieved through the addition of W that has as a result the complete amorphization of ZnO as indicated by the absence of any diffraction peaks. In order to better observe the shift of main peaks as a function of the doping element, in Figure 4b diffractograms are plotted only in a limited 2θ range (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). The addition of dopants leads to a shift of the peaks toward lower 2θ angles, in the following order: Ti:ZnO, Zr:ZnO, and the stronger effect is observed for Mn:ZnO.…”

“…Using Debye-Scherrer Equation (7), the crystallite size (D) of pristine and doped-ZnO was calculated ( Table 2), with the exception of the Mn:ZnO for which the main peak lacks the symmetry characteristic to a single phase as already mentioned before, as well as W:ZnO that shows no peaks at all. [36]…”

Annealing Conditions’ Influence on the Oxidation of Silicon‐Aluminium‐Alloys in Combinatorial Thin‐Film Libraries

“…It was described that the high‐ CPD element at low concentrations (“minority species”) seems not to have an influence on the CPD at high concentrations of the lower‐ CPD ‐valued element (in this case Al). It is also reported that changes in surface morphology (which are not measurable by SKP as their size (surface roughness) is below the vibrational amplitude of the SKP tip) may have a contribution to the measured Volta potentials . The plateau in CPD values for aluminium concentrations exceeding 50 at.% may indicate an inclusion of silicon atoms in the deposited Al‐rich thin‐film region.…”

Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements

“…Analysis of thin films was preferred against analyzing of bulk materials because of the highly homogenous surface of sputtered and thermally evaporated samples. Thin films of sputtered Mn, Mo, W, and thermally evaporated Zn thin films are known to have smooth surfaces. It is proven, that scratches, cracks or even residuals from polishing agents have an effect on the Volta potential of a surface .…”