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Tunable negative thermal expansion and structural evolution in antiperovskite Mn 3 Ga 1− x Ge x N (0 ≤ x ≤ 1.0)
Author(s) -
Lu Huiqing,
Sun Ying,
Deng Sihao,
Shi Kewen,
Wang Lei,
Zhao Wenjun,
Han Huimin,
Deng Shenghua,
Wang Cong
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15099
Subject(s) - antiperovskite , negative thermal expansion , tetragonal crystal system , thermal expansion , materials science , crystallography , atmospheric temperature range , crystal structure , diffraction , analytical chemistry (journal) , chemistry , thermodynamics , nanotechnology , metallurgy , physics , optics , nitride , layer (electronics) , chromatography
The negative thermal expansion ( NTE ) and structural evolution of antiperovskite compounds Mn 3 Ga 1− x Ge x N (0 ≤ x ≤ 1.0) were systematically investigated. Our results indicate the crystal structure of Mn 3 Ga 1− x Ge x N changes from cubic ( C ) to tetragonal ( T 4 ) with increasing Ge content by X‐ray diffraction ( XRD ).The negative thermal expansion from x = 0 (operation‐temperature range ▵ T = 20 K) to x = 0.4 (▵ T = 60 K) becomes broad and shifts to higher temperature, and then it became positive from x = 0.5 in Mn 3 Ga 1− x Ge x N. Typically, Mn 3 Ga 0.5 Ge 0.5 N shows low thermal expansion behavior between 300 and 450 K (∆ T = 150 K), and thermal expansion coefficient α is estimated to be 2 × 10 −6 K −1 . Furthermore, variable temperature XRD was measured to reveal the origin of NTE . The cubic I ‐ cubic II phases coexistence ( x = 0.2) and cubic I ‐ tetragonal coexistence ( x = 0.5, 0.6) was observed at low temperature. The tunable NTE is highly valuable for practical applications in precision devices.