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Structural, Magnetic and Thermoelectric Properties of hp ‐Mn 3 Ge 5
Author(s) -
Castillo Rodrigo,
Schnelle Walter,
Bobnar Matej,
CardosoGil Raul,
Schwarz Ulrich,
Grin Yuri
Publication year - 2020
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201900342
Subject(s) - tetragonal crystal system , thermoelectric effect , materials science , fermi level , condensed matter physics , seebeck coefficient , ferromagnetism , density of states , manganese , electrical resistivity and conductivity , heusler compound , thermal conductivity , band gap , crystal structure , crystallography , chemistry , metallurgy , physics , thermodynamics , quantum mechanics , composite material , electron
Mn 3 Ge 5 was obtained by high‐pressure, high temperature synthesis. The compound adopts a Nowotny‐Chimney‐Ladder type crystal structure [tetragonal, space group P 4 n 2, a = 5.7449(1) Å, c = 13.9096(4) Å, Z = 4]. Magnetic measurements reveal a ferromagnetic transition around 40 K and metallic conductivity in the temperature range from 3 K to 350 K. Despite a low thermal conductivity, the metallic character of the sample and the low Seebeck coefficient result in low values for the thermoelectric Figure of merit, ZT . Band‐structure calculations show that the Fermi level is located slightly below a pseudo‐gap in the electronic density of states. Chemical bonding analysis in position space discloses moderate charge transfer and two‐ as well as three‐atomic directed, heteroatomic bonding involving both the manganese and the germanium atoms.