Ferromagnetic ordering in alkali-metal iron antimonides: NaFe4Sb12 and KFe4Sb12.
New alkali-metal compounds with the filled-skutterudite structure were synthesized and their chemical and physical properties investigated. X-ray diffraction, microprobe, and chemical analysis established the structure and the composition without defects on the cation site. Magnetization, ac susceptibility, specific heat, resistivity, and NMR or NQR demonstrated NaFe4Sb12 to be ferromagnetic below approximately 85 K and to exhibit an additional magnetic anomaly around 40 K. Band structure calculations find a large density of states at the Fermi energy and a ferromagnetic ground state. Similar behavior was observed for KFe4Sb12.
Leithe-Jasper
A
A
Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Strasse 40, 01187 Dresden, Germany. jasper@cpfs.mpg.de
Schnelle
W
W
Rosner
H
H
Senthilkumaran
N
N
Rabis
A
A
Baenitz
M
M
Gippius
A
A
Morozova
E
E
Mydosh
J A
JA
Grin
Y
Y