scholarly journals DESY NanoLab

Author(s):  
Andreas Stierle ◽  
Thomas F. Keller ◽  
Heshmat Noei ◽  
Vedran Vonk ◽  
Ralf Roehlsberger

The DESY NanoLab is a facility providing access to nano-characterization, nano-structuring and nano-synthesis techniques which are complementary to the advanced X-ray techniques available at DESY’s light sources. It comprises state-of-the art scanning probe microscopy and focused ion beam manufacturing, as well as surface sensitive spectroscopy techniques for chemical analysis. Specialized laboratory x-ray diffraction setups are available for a successful sample pre-characterization before the precious synchrotron beamtimes. Future upgrades will include as well characterization of magnetic properties.

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.


CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.


2015 ◽  
Vol 821-823 ◽  
pp. 100-103
Author(s):  
Ta Ching Hsiao ◽  
Shen Tsao ◽  
Sergey Nagalyuk ◽  
Evgeny Mokhov

A specific transition metal is used as a dopant element in silicon carbide powders to create the compensation effect. According to ab-initio simulation, vanadium, chromium, and manganese-induced compensation decrease the lifetime of the acceptor carrier and cause higher resistance when boron is the main impurity. Since the silicon carbide lattice has low solubility, excess metal precipitates on the surface of powders, particularly on the grain boundaries. The compositions of matrix and precipitation in the powders reveal obvious differences between the two areas. The X-ray diffraction (XRD) pattern shows the structure of VSi2, which indicates the existence of a second phase. Dual-beam focused ion beam (DBFIB) is used to further analyze the geography inside the powders. A cross-section view by DBFIB shows a second phase in the grains with a composition similar to that in the grain boundary. Metal-doped silicon carbide powders are used as starting materials to conduct crystal growth with better dopant element distribution.


2016 ◽  
Vol 35 (6) ◽  
pp. 551-557 ◽  
Author(s):  
Omid Amiri ◽  
Mohammad Reza Mozdianfar ◽  
Mahmoud Vahid ◽  
Masoud Salavati-Niasari ◽  
Sousan Gholamrezaei

AbstractBiFeO3 nanopowders with new morphology have been synthesized by different methods. X-ray diffraction analysis, scanning electron microscopy, Fourier transform infrared and vibrating sample magnetometer were carried out at room temperature to study the structural and magnetic properties of as-synthesized products. VSM was utilized to measure the size-dependent magnetic behaviors of the as-prepared nanoparticles. Results show that the method has strong effect on the purity of the products. BFO synthesized by third method was pure. Crystallite size has a great effect on the magnetic properties. According to these results the nanoparticle diameter is smaller than the critical single-domain diameter, avoiding the configuration of magnetic domain walls decreases the magnetization. Even though the diameter of particle becomes even smaller, the thermal stability of the magnetization orientation decreases.


1988 ◽  
Vol 126 ◽  
Author(s):  
John F. Knudsen ◽  
R. C. Bowman ◽  
P. M. Adams ◽  
R. Newman ◽  
J. P. Hurrell ◽  
...  

ABSTRACTEpitaxial regrowth of deposited amorphous silicon has been previously described utilizing ion implantation amorphization, ion mixing and thermal anneal. This paper evaluates the effects of these process steps on crystalline quality utilizing Rutherford Backscattering (RBS), x-ray diffraction rocking curves and Raman scattering.In situ (during implantation) regrowth results in defective crystallinity. In contrast, when there is no in situ regrowth, the post anneal crystallinity is equivalent by RBS and x-ray evaluation to virgin single crystal wafers. In situ regrowth is most pronounced during the high beam current ion mixing type implants which produce wafer temperatures of about 250°C. The final crystalline quality which results from different sequences of amorphization and ion mixing implants, is strongly dependent upon the amount of in situ regrowth which has occurred. The greater the in situ regrowth the poorer the final crystalline quality.


2012 ◽  
Vol 1433 ◽  
Author(s):  
Andrew A. Woodworth ◽  
Ali Sayir ◽  
Philip G. Neudeck ◽  
Balaji Raghothamachar ◽  
Michael Dudley

ABSTRACTCommercially available bulk silicon carbide (SiC) has a high number (>2000/cm2) of screw dislocations (SD) that have been linked to degradation of high-field power device electrical performance properties. Researchers at the NASA Glenn Research Center have proposed a method to mass-produce significantly higher quality bulk SiC. In order for this bulk growth method to become reality, growth of long single crystal SiC fibers must first be achieved. Therefore, a new growth method, Solvent-Laser Heated Floating Zone (Solvent-LHFZ), has been implemented. While some of the initial Solvent-LHFZ results have recently been reported, this paper focuses on further characterization of grown crystals and their growth fronts. To this end, secondary ion mass spectroscopy (SIMS) depth profiles, cross section analysis by focused ion beam (FIB) milling and mechanical polishing, and orientation and structural characterization by X-ray transmission Laue diffraction patterns and X-ray topography were used. Results paint a picture of a chaotic growth front, with Fe incorporation dependant on C concentration.


Sign in / Sign up

Export Citation Format

Share Document