Time-Resolved Study of Pd-Os and Pt-Os Nanoalloys Formation through Thermal Decomposition of [Pd(NH3)4][OsCl6] and [Pt(NH3)4][OsCl6] Complex Salts Научная публикация
| Журнал |
Materials Research Bulletin
ISSN: 0025-5408 |
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| Вых. Данные | Год: 2021, Том: 144, Номер статьи : 111511, Страниц : 17 DOI: 10.1016/j.materresbull.2021.111511 | ||||||||
| Ключевые слова | Alloy; Complex salt; Nanoparticles formation; Single-source precursors; XAFS | ||||||||
| Авторы |
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| Организации |
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Информация о финансировании (3)
| 1 | Российский фонд фундаментальных исследований | 19-02-00308 (АААА-А19-119011590024-7) |
| 2 | Министерство образования и науки Российской Федерации | FWUZ-2021-0002 (121031700315-2) |
| 3 | The French National Research Agency | ANR10-EQPX-45 |
Реферат:
The formation mechanisms of Pd-Os and Pt-Os alloys in the course of thermal decomposition of iso-formular and isostructural complex salts [Pd(NH3)4][OsCl6] and [Pt(NH3)4][OsCl6] in an inert atmosphere have been studied by
in-situ QXAFS, XPS and PXRD. The mechanisms of thermal decomposition of the precursors are found to differ from each other, but the detected intermediate products show no significant effect on the local atomic structure around Os, Pt/Pd in their final products. A crystalline beta-trans-[Pd(NH3)2Cl2] intermediate of the first step of thermal decomposition of [Pd(NH3)4][OsCl6] makes the anion [OsCl6]2− transform differently than that of [Pt(NH3)4][OsCl6]. It transforms into a short-lived [Os(NH3)xCl6-x] (2≤x≤4), and then to a distorted octahedron [OsCl6]2−, similar to the high-temperature modification of OsCl4. In case of [Pt(NH3)4][OsCl6], the intermediate [Os(NH3)2Cl4] modifies into four chlorine coordinated Os,{OsCl4}0/1−. Consecutive reduction of Pd(II)/Pt(II) and Os(IV) to the metals defines the homophilic atomic order with the fcc-Pd covered by a random Pd-Os alloy layer and Os on the surface, that is supported by High-Resolution Transmission Electron Mictroscopy (HRTEM) and Scanning TEM (STEM) energy dispersive X-ray (EDX) data, and the diffusion direction going from the surface (hcp-Os) to bulk (fcc-Pd/Pt). As a result, the heterogeneous alloys are formed with a very similar electronic and local atomic structure of Os and Pd/Pt. Upon alloying, the Os 5d5/2,3/2 and Pt 5d5/2,3/2 levels are depleted in the Pt-Os alloys compared to dispersed hcp-Os,
fcc-Pt, and Pt foil. This is an unusual behaviour for Os and Pt, calling into question the versatility of d-band theory in bimetallic Os-alloys. The spin-orbit effect at the Os site has been found for both the Pd-Os and Pt-Os alloys, but it is about 4 times less compared to the complex salts. The obtained values for the complex compounds are comparable with those for the iridates, proposed as materials with spin-orbit-induced properties.
Библиографическая ссылка:
Asanova T.I.
, Asanov I.P.
, Yusenko K.V.
, La Fontaine C.
, Gerasimov E.Y.
, Zadesenets A.V.
, Korenev S.V.
Time-Resolved Study of Pd-Os and Pt-Os Nanoalloys Formation through Thermal Decomposition of [Pd(NH3)4][OsCl6] and [Pt(NH3)4][OsCl6] Complex Salts
Materials Research Bulletin. 2021. V.144. 111511 :1-17. DOI: 10.1016/j.materresbull.2021.111511 WOS Scopus РИНЦ CAPlus OpenAlex
Time-Resolved Study of Pd-Os and Pt-Os Nanoalloys Formation through Thermal Decomposition of [Pd(NH3)4][OsCl6] and [Pt(NH3)4][OsCl6] Complex Salts
Materials Research Bulletin. 2021. V.144. 111511 :1-17. DOI: 10.1016/j.materresbull.2021.111511 WOS Scopus РИНЦ CAPlus OpenAlex
Даты:
| Поступила в редакцию: | 28 апр. 2021 г. |
| Принята к публикации: | 29 июл. 2021 г. |
| Опубликована online: | 3 авг. 2021 г. |
| Опубликована в печати: | 1 дек. 2021 г. |
Идентификаторы БД:
| Web of science: | WOS:000697270400007 |
| Scopus: | 2-s2.0-85112133637 |
| РИНЦ: | 46961425 |
| Chemical Abstracts: | 2021:1765994 |
| OpenAlex: | W3187360844 |