Solid state synthesis of Mn{sub 5}Ge{sub 3} in Ge/Ag/Mn trilayers: Structural and magnetic studies

Journal Article · Wed Feb 15 00:00:00 EST 2017 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2016.12.010· OSTI ID:22658209

Myagkov, V. G.; Bykova, L. E.; Matsynin, A. A.; Volochaev, M. N.; Zhigalov, V. S.; Tambasov, I. A. ^[1]; Mikhlin, Yu L. ^[2]; Velikanov, D. A. ^[1]; Bondarenko, G. N. ^[2]

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1. Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation)
2. Institute of Chemistry and Chemical Technology, SB RAS, Krasnoyarsk 660049 (Russian Federation)

The thin-film solid-state reaction between elemental Ge and Mn across chemically inert Ag layers with thicknesses of (0, 0.3, 1 and 2.2 µm) in Ge/Ag/Mn trilayers was studied for the first time. The initial samples were annealed at temperatures between 50 and 500 °C at 50 °C intervals for 1 h. The initiation temperature of the reaction for Ge/Mn (without a Ag barrier layer) was ~ 120 °C and increased slightly up to ~ 250 °C when the Ag barrier layer thickness increased up to 2.2 µm. In spite of the Ag layer, only the ferromagnetic Mn{sub 5}Ge{sub 3} compound and the Nowotny phase were observed in the initial stage of the reaction after annealing at 500 °C. The cross-sectional studies show that during Mn{sub 5}Ge{sub 3} formation the Ge is the sole diffusing species. The magnetic and cross-sectional transmission electron microscopy (TEM) studies show an almost complete transfer of Ge atoms from the Ge film, via a 2.2 µm Ag barrier layer, into the Mn layer. We attribute the driving force of the long-range transfer to the long-range chemical interactions between reacting Mn and Ge atoms. - Graphical abstract: The direct visualization of the solid state reaction between Mn and Ge across a Ag buffer layer at 500 °C. - Highlights: • The migration of Ge, via an inert 2.2 µm Ag barrier, into a Mn layer. • The first Mn{sub 5}Ge{sub 3} phase was observed in reactions with different Ag layers. • The Ge is the sole diffusing species during Mn{sub 5}Ge{sub 3} formation • The long-range chemical interactions control the Ge atomic transfer.

• OSTI ID: 22658209
• Journal Information: Journal of Solid State Chemistry, Vol. 246; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CRYSTAL STRUCTURE
DEPLETION LAYER
GERMANIUM COMPOUNDS
MANGANESE COMPOUNDS
SILVER COMPOUNDS
THIN FILMS