Prototyping iridium coated mirrors for x-ray astronomy

Döhring, Thorsten; Probst, Anne-Catherine; Stollenwerk, Manfred; Emmerich, Florian; Stehlikova, Veronika; Inneman, A.

doi:10.1117/12.2265931

Cited by 3 publications

(3 citation statements)

References 4 publications

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“…These properties make Ir useful for many technological applications; for instance, as a high-pressure gasket or as a pressure calibrant in high temperature and high-pressure (HP) diamond-anvil cell (DAC) experiments. On the other hand, Ir is used for the construction of thermocouples and encapsulators of nuclear-powered electrical generators in space technology 2 . Furthermore, Ir is being currently used to synthesize Ir-based double perovskite compounds and iridium-based transition metal oxides or iridates, and its application fields stand from high-temperature superconductivity 3 , magnetoresistance 4 , to multiferroicity 5 .…”

Section: Introductionmentioning

confidence: 99%

Phase stability and electronic structure of iridium metal at the megabar range

Monteseguro

Sans

Cuartero

et al. 2019

Sci Rep

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The 5d transition metals have attracted specific interest for high-pressure studies due to their extraordinary stability and intriguing electronic properties. In particular, iridium metal has been proposed to exhibit a recently discovered pressure-induced electronic transition, the so-called core-level crossing transition at the lowest pressure among all the 5d transition metals. Here, we report an experimental structural characterization of iridium by x-ray probes sensitive to both long- and short-range order in matter. Synchrotron-based powder x-ray diffraction results highlight a large stability range (up to 1.4 Mbar) of the low-pressure phase. The compressibility behaviour was characterized by an accurate determination of the pressure-volume equation of state, with a bulk modulus of 339(3) GPa and its derivative of 5.3(1). X-ray absorption spectroscopy, which probes the local structure and the empty density of electronic states above the Fermi level, was also utilized. The remarkable agreement observed between experimental and calculated spectra validates the reliability of theoretical predictions of the pressure dependence of the electronic structure of iridium in the studied interval of compressions.

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Section: Introductionmentioning

confidence: 99%

Phase stability and electronic structure of iridium metal at the megabar range

Monteseguro

Sans

Cuartero

et al. 2019

Sci Rep

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“…Silicon plates provided by the company Cosine, representative of the substrates that will be used for the fabrication of ATHENA's optics, have been coated at two facilities; the DC magnetron sputtering chamber at Smithsonian Astrophysical Observatory (SAO) and the DC magnetron sputtering chamber at Aschaffenburg University (THAB). The two facilities differ for the different control of minimal thickness and for the different optimization of the process for these coatings, which are routinely manufactured in both facilities [21][22][23][24][25][26][27][28][29] , which also have developed methods to control stress in this kind of films [24][25] . The SAO facility has a finer control of the deposited thickness and can produce nanometric or subnanometric thickness films made of sputtered metals layers.…”

Section: Coatings and Overcoatings On Silicon Substrates Deposition And Characterization Of Metallic Layersmentioning

confidence: 99%

Development of low-density coatings for soft x-ray reflectivity enhancement for ATHENA and other missions

Cotroneo

Bruni

Döhring

et al. 2021

International Conference on Space Optics — ICSO 2020

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Metallic coatings made of precious metals (e.g. Ir, Pt or Au) with high atomic number Z have been traditionally employed at grazing incidence for X-rays reflection and focalization. These materials offer a range of reflection extended to higher energies, but also present a series of absorption edges, which limit the reflectivity in the 2-4 keV band and below.Therefore the search for alternative coatings, able to improve the reflection in the soft energy range, is particularly relevant for the development of future telescopes, like ATHENA (ESA), Lynx (NASA) and eXTP (CAS).Low-Z overcoatings (e.g. carbon or B4C), applied on top of the high-Z metallic layer, can enhance the reflectivity in the softer band (mainly below 2 keV), but conventional deposition methods for these materials are not easily compatible with some of the mainstream technologies for mirror fabrication (notably, the silicon pore optics that will be used for the ATHENA X-ray mission which is being implemented by ESA).In this work we discuss novel solutions (carbon-like overcoatings realized by dip coating or vapor phase deposition), which can be particularly convenient for the application to ATHENA and to future telescopes.

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“…Iridium is one of the most corrosion-resistant elements, even at very high temperatures [1]. This predisposes iridium and its alloys to use in space applications [2,3] and catalysis [4][5][6][7][8][9]. Iridium and its complexes can also be used in the medical field as therapeutic reagents [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Phase Equilibria of the Ho-Ir-O Ternary System at 1073 K

Homolová,

Čiripová,

Zobač

et al. 2023

Materials

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An experimental study of the phase equilibria of the Ho-rich part of the Ho-Ir-O ternary system at 1073 K by means of x-ray diffraction, differential scanning calorimetry, and scanning electron microscopy has been carried out. Ho-hcp and four binary compounds, namely Ho3Ir, Ho5Ir2, Ho5Ir3, and Ho2O3, were identified in the Ho-Ir-O model alloys after long-term annealing (350–1220 h). No solubility of iridium in Ho2O3 oxide and Ho-hcp was observed. No ternary phase was found. Based on the experimental results, an isothermal section of the Ho-rich part of the Ho-Ir-O system at 1073 K was constructed. In addition, the microstructure of as-cast alloys was studied. An irregular eutectic consisting of faceted Ho-phase in Ho3Ir phase was observed in the alloys with Ho-hcp + Ho3Ir + Ho2O3 phase composition, and the temperature of the eutectic reaction Ho-hcp + Ho3Ir ↔ liquid was determined.

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Prototyping iridium coated mirrors for x-ray astronomy

Cited by 3 publications

References 4 publications

Phase stability and electronic structure of iridium metal at the megabar range

Phase stability and electronic structure of iridium metal at the megabar range

Development of low-density coatings for soft x-ray reflectivity enhancement for ATHENA and other missions

Experimental Investigation of Phase Equilibria of the Ho-Ir-O Ternary System at 1073 K

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