非表示:
キーワード:
-
要旨:
The rock-salt ordered type double perovskite Sr2InReO6 is systematically
investigated by means of powder x-ray diffraction, neutron powder
diffraction, temperature-dependent electrical transport, heat capacity
and magnetic susceptibility measurements, and electronic band structure
calculations. The crystal structure of Sr2InReO6 is revised to be
monoclinic (cryolite structure type, space group P2(1)/n) with all
structural distortions according to the high-symmetry aristotype due to
tilting of the InO6 and ReO6 octahedra, respectively. Sr2InReO6 is a
Mott insulator with variable-range hopping. Two 5d electrons are
unpaired and localized on the Re5+ ions. Although there are
antiferromagnetic interactions, the fcc arrangement of the Re5+ cations
(5d(2)) leads to a geometrically frustrated spin system that does not
achieve full magnetic order. The experimental findings are in line with
the results of electronic structure computation using the WIEN2K program
within the GGA + U approximation exclusively on the basis of the revised
crystal structure model.
