A compact high vacuum heating chamber for <i>in-situ</i> x-ray scattering studies

Bertram, Florian; Deiter, C.; Pflaum, K.; Seeck, O. H.

doi:10.1063/1.4746290

Cited by 4 publications

(2 citation statements)

References 27 publications

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“…For the structural characterization of the entire film, untreated samples are investigated using in situ X-ray diffraction (XRD) measurements carried out in a modified version of the high vacuum (HV) reaction chamber (base pressure 10 À8 mbar) presented in ref. 25. The heating stage has been modified to enable resistive heating and an IR pyrometer was added for temperature control.…”

Section: Methodsmentioning

confidence: 99%

Structural transitions of epitaxial ceria films on Si(111)

Wilkens

Schuckmann

Oelke

et al. 2013

Phys. Chem. Chem. Phys.

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The structural changes of a (111) oriented CeO2 film grown on a Si(111) substrate covered with a hex-Pr2O3(0001) interface layer due to post deposition annealing are investigated. X-ray photoelectron spectroscopy measurements revealing the near surface stoichiometry show that the film reduces continuously upon extended heat treatment. The film is not homogeneously reduced since several coexisting crystalline ceria phases are stabilized due to subsequent annealing at different temperatures as revealed by high resolution low energy electron diffraction and X-ray diffraction. The electron diffraction measurements show that after annealing at 660 °C the ι-phase (Ce7O12) is formed at the surface which exhibits a (√7 × √7)R19.1° structure. Furthermore, a (√27 × √27)R30° surface structure with a stoichiometry close to Ce2O3 is stabilized after annealing at 860 °C which cannot be attributed to any bulk phase of ceria stable at room temperature. In addition, it is shown that the fully reduced ceria (Ce2O3) film exhibits a bixbyite structure. Polycrystalline silicate (CeSi(x)O(y)) and crystalline silicide (CeSi1.67) are formed at 850 °C and detected at the surface after annealing above 900 °C.

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Section: Methodsmentioning

confidence: 99%

Structural transitions of epitaxial ceria films on Si(111)

Wilkens

Schuckmann

Oelke

et al. 2013

Phys. Chem. Chem. Phys.

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“…We show here that nanobeam sample environments with wide temperature ranges and control over ambient conditions can resolve these challenges. We build on concepts developed for previous compact sample environments, 14,15 and minimize both the mass of the overall structure and the stiffness of its connections to auxiliary equipment such as pumps and power supplies. We present detailed descriptions and experimental tests of ultrahigh vacuum (UHV) sample environments with low masses and compact shapes that allow them to be integrated with nanobeam diffractometers.…”

Section: Introductionmentioning

confidence: 99%

Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging

Evans

Chahine

Grifone

et al. 2013

Review of Scientific Instruments

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X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 1-2 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.

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