Identifying the electronic character and role of the Mn states in the valence band of (Ga,Mn)As

We report high-resolution hard x-ray photoemission spectroscopy results on (Ga,Mn)As films as a function of Mn doping. Supported by theoretical calculations we identify, over the entire 1% to 13% Mn doping range, the electronic character of the states near the top of the valence band. Magnetization and temperature dependent core-level photoemission spectra reveal how the delocalized character of the Mn states enables the bulk ferromagnetic properties of (Ga,Mn)As.Comment: prl submitte

Low-temperature luminescence spectrum of forbidden 4f135d‐4f144f^{13} 5d‐4f^{14} transitions in CaF2:Lu3+CaF_2:Lu^{3+} crystal

$Lu^{3+}$ + $4f^{13} 5d‐4f^{14}$ luminescence in $CaF_2:Lu^{3+}$ crystal at 8 K was studied with a high spectral resolution using synchrotron radiation excitation. Absence of a zero-phonon line in the recorded spectrum was explained and features in the recorded spectrum were reproduced by simulation based on the microscopic model of electron-phonon interaction and the developed theory of non-Condon spectra

Microbial Identification, High-Resolution Microscopy and Spectrometry of the Rhizosphere in Its Native Spatial Context

During the past decades, several stand-alone and combinatorial methods have been developed to investigate the chemistry (i.e., mapping of elemental, isotopic, and molecular composition) and the role of microbes in soil and rhizosphere. However, none of these approaches are currently applicable to characterize soil-root-microbe interactions simultaneously in their spatial arrangement. Here we present a novel approach that allows for simultaneous microbial identification and chemical analysis of the rhizosphere at micro− to nano-meter spatial resolution. Our approach includes (i) a resin embedding and sectioning method suitable for simultaneous correlative characterization of Zea mays rhizosphere, (ii) an analytical work flow that allows up to six instruments/techniques to be used correlatively, and (iii) data and image correlation. Hydrophilic, immunohistochemistry compatible, low viscosity LR white resin was used to embed the rhizosphere sample. We employed waterjet cutting and avoided polishing the surface to prevent smearing of the sample surface at nanoscale. The quality of embedding was analyzed by Helium Ion Microscopy (HIM). Bacteria in the embedded soil were identified by Catalyzed Reporter Deposition-Fluorescence in situ Hybridization (CARD-FISH) to avoid interferences from high levels of autofluorescence emitted by soil particles and organic matter. Chemical mapping of the rhizosphere was done by Scanning Electron Microscopy (SEM) with Energy-dispersive X-ray analysis (SEM-EDX), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), nano-focused Secondary Ion mass Spectrometry (nanoSIMS), and confocal Raman spectroscopy (μ-Raman). High-resolution correlative characterization by six different techniques followed by image registration shows that this method can meet the demanding requirements of multiple characterization techniques to identify spatial organization of bacteria and chemically map the rhizosphere. Finally, we presented individual and correlative workflows for imaging and image registration to analyze data. We hope this method will be a platform to combine various 2D analytics for an improved understanding of the rhizosphere processes and their ecological significance

Thermoelectric properties of CoTiSb based compounds

Several CoTiSb based compounds were synthesized and investigated on their thermoelectric properties. The aim was to improve the thermoelectric properties of CoTiSb by the systematic substitution of atoms or the introduction of additional Co into the vacant sublattice. The solid solutions Co(1+x)TiSb, Co(1-y)Cu(y) TiSb and CoTiSb(1-z)Bi(z) were synthesized. X-ray diffraction was used to investigate the crystal structure. The resistivity, the Seebeck coefficient and the thermal conductivity were determined for all compounds in the temperature range from 2 to 400 K. The highest figure of merit for each solid solution is presented. We were able to improve the figure of merit by a factor of approximately seven

Identification of nanoparticles and their localization in algal biofilm by 3D-imaging secondary ion mass spectrometry

ToF-SIMS boundaries were pushed to enhance lateral resolution and mass resolving power for chemical imaging of nanoparticles in biological systems

Publication Data for Bandara et al 2021 - Front.Plant.Sci LRWhite Embedding Method

Data acquired in the framework of the SPP 2089, funded by the DFG. This data folder associated with the publication "Microbial Identification, High-Resolution Microscopy and Spectrometry of the Rhizosphere in its Native Spatial Context" by Bandara et al. (2021), Frontiers in Plant Science Journal. DOI: 10.3389/fpls.2021.668929 The compressed folder contains ten subfolders corresponding to each technique as described below. Each folder named as Origin contains the original data, while processed data is included in the folder named as Export. In total there are 251 files. 1. CARD-FISH: This folder contains Epifluorescence micrographs presented in Figure 8d and 10a. Original data format is .czi from Carl Zeiss imaging. Exported images format is .tif. Folder contains two folders for individual samples. 2. Correlia_Registered_Datasets This folder contains two Correlia (https://www.ufz.de/correlia) projects used to register different microscopy images presented in Figure 8d and Figure9. 3. DarkField_Figure3_Map This folder contains stitched darkfield micrographs of CY0211 sample (Figure3). Text file contains the imaging information. 4. Epifluorescence This folder contains Epifluorescence images presented in Figure3, Figure 10 5. HIM This folder contains Helium ion micrographs presented in Figure 2 and Figure 6d 6. nanoSIMS This folder contains nanoSIMS data presented in Figure 6 and Figure 10 7. Raman This folder contains confocal Raman Microscopy data presented in Figure 7 8. Roughness Measurements This folder contains surface profile data presented in Figure 2b 9. SEM-EDX This folder contains SEM and EDX data presented in Figure 5 and Figure 8d 10.ToFSIMS This folder contains ToFSIMS data presented in Figure 4 Funding: This data was produced within the framework of the priority program SPP 2089, “Rhizosphere spatiotemporal organization-a key to rhizosphere functions” funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 403641683 (RI-903/7-1). Research work of Yalda Devoudpour was supported by Deutsche Forschungsgemeinschaft Integration of Refugee Scientists and Academics

Publication Data for Bandara et al 2021 - Front.Plant.Sci LRWhite Embedding Method

Data acquired in the framework of the SPP 2089, funded by the DFG. This data folder associated with the publication "Microbial Identification, High-Resolution Microscopy and Spectrometry of the Rhizosphere in its Native Spatial Context" by Bandara et al. (2021), Frontiers in Plant Science Journal. DOI: 10.3389/fpls.2021.668929 The compressed folder contains ten subfolders corresponding to each technique as described below. Each folder named as Origin contains the original data, while processed data is included in the folder named as Export. In total there are 251 files. 1. CARD-FISH: This folder contains Epifluorescence micrographs presented in Figure 8d and 10a. Original data format is .czi from Carl Zeiss imaging. Exported images format is .tif. Folder contains two folders for individual samples. 2. Correlia_Registered_Datasets This folder contains two Correlia (https://www.ufz.de/correlia) projects used to register different microscopy images presented in Figure 8d and Figure9. 3. DarkField_Figure3_Map This folder contains stitched darkfield micrographs of CY0211 sample (Figure3). Text file contains the imaging information. 4. Epifluorescence This folder contains Epifluorescence images presented in Figure3, Figure 10 5. HIM This folder contains Helium ion micrographs presented in Figure 2 and Figure 6d 6. nanoSIMS This folder contains nanoSIMS data presented in Figure 6 and Figure 10 7. Raman This folder contains confocal Raman Microscopy data presented in Figure 7 8. Roughness Measurements This folder contains surface profile data presented in Figure 2b 9. SEM-EDX This folder contains SEM and EDX data presented in Figure 5 and Figure 8d 10.ToFSIMS This folder contains ToFSIMS data presented in Figure 4 Funding: This data was produced within the framework of the priority program SPP 2089, “Rhizosphere spatiotemporal organization-a key to rhizosphere functions” funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 403641683 (RI-903/7-1). Research work of Yalda Devoudpour was supported by Deutsche Forschungsgemeinschaft Integration of Refugee Scientists and Academics

Anaerobic oxidation of ethane by archaea from a marine hydrocarbon seep

Ethane is the second most abundant component of natural gas in addition to methane, and—similar to methane—is chemically unreactive. The biological consumption of ethane under anoxic conditions was suggested by geochemical profiles at marine hydrocarbon seeps1,2,3, and through ethane-dependent sulfate reduction in slurries4,5,6,7. Nevertheless, the microorganisms and reactions that catalyse this process have to date remained unknown8. Here we describe ethane-oxidizing archaea that were obtained by specific enrichment over ten years, and analyse these archaea using phylogeny-based fluorescence analyses, proteogenomics and metabolite studies. The co-culture, which oxidized ethane completely while reducing sulfate to sulfide, was dominated by an archaeon that we name ‘Candidatus Argoarchaeum ethanivorans’; other members were sulfate-reducing Deltaproteobacteria. The genome of Ca. Argoarchaeum contains all of the genes that are necessary for a functional methyl-coenzyme M reductase, and all subunits were detected in protein extracts. Accordingly, ethyl-coenzyme M (ethyl-CoM) was identified as an intermediate by liquid chromatography–tandem mass spectrometry. This indicated that Ca. Argoarchaeum initiates ethane oxidation by ethyl-CoM formation, analogous to the recently described butane activation by ‘Candidatus Syntrophoarchaeum’9. Proteogenomics further suggests that oxidation of intermediary acetyl-CoA to CO2 occurs through the oxidative Wood–Ljungdahl pathway. The identification of an archaeon that uses ethane (C2H6) fills a gap in our knowledge of microorganisms that specifically oxidize members of the homologous alkane series (CnH2n+2) without oxygen. Detection of phylogenetic and functional gene markers related to those of Ca. Argoarchaeum at deep-sea gas seeps10,11,12 suggests that archaea that are able to oxidize ethane through ethyl-CoM are widespread members of the local communities fostered by venting gaseous alkanes around these seeps