TY  - THES
AB  - This thesis deals with the synthesis, structure determination and investigation of the properties of Cr 2 Ge 2 Se 6 , Mn 2 GeSe 4 , Fe 3 GeTe 2 and Ni 3 GeTe 2 . Mn 2 GeSe 4 crystallizes in the orthorhombic space group Pnma (a=1335,0(3) pm, b = 776,5(2) pm, c = 630,7(1) pm) is one of the rare ternary transition metal selenides representatives of the olivine ((Fe, Mg) 2 SiO 4 ) structure - type. Fe 3 GeTe 2 and Ni 3 GeTe 2 are the first ternary members of the filled NiAs - structures. Both crystallize in the hexagonal group P6 3 /mmc (a = b = 399,1(1) pm, c=1633,6(3) pm for Fe 3 GeTe 2 and a = b = 319,1(1) pm, c=1602,2(3) pm for Ni 3 GeTe 2 , respectively). Their structures are characterized by alternating layer packages, each one built of five layers. Cr 2 Ge 2 Se 6 is a new compound belonging to the the M 2 X 2 Y 6 (M = transition metal, X = Si, Ge, Y = chalcogen) structure family. X - ray powder diffraction investigations find a hexagonal symmetry. The lattice constants are a = b = 629,3(3) pm, c = 1942,1(6) pm, γ = 120°. Magnetic properties studies show antiferromagnetic interactions in Mn 2 GeSe 4 and ferromagnetic spin ordering in Fe 3 GeTe 2 . Ni 3 GeTe 2 exhibits weak paramagnetism.
AU  - Aleksandrov, Krasimir
DA  - 2005
KW  - Chalkogenide
KW  - Germanide
KW  - Kristallstruktur
LA  - eng
PY  - 2005
TI  - Preparation, structure and properties of new ternary chalcogenides and germanides of the metals from the first transition series, Cr, Mn, Fe and Ni
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:467-1058
Y2  - 2024-11-24T17:59:24
ER  -