Ferromagnetism in the Mott insulator Ba2NaOsO6.
Results are presented of single crystal structural, thermodynamic, and reflectivity measurements of the double-perovskite Ba2NaOsO6. These characterize the material as a 5d1 ferromagnetic Mott insulator with an ordered moment of approximately 0.2microB per formula unit and TC=6.8(3) K. The magnetic entropy associated with this phase transition is close to Rln2, indicating that the quartet ground state anticipated from consideration of the crystal structure is split, consistent with a scenario in which the ferromagnetism is associated with orbital ordering.
Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, California 94305, USA.
A S
AS
Erickson
S
S
Misra
G J
GJ
Miller
R R
RR
Gupta
Z
Z
Schlesinger
W A
WA
Harrison
J M
JM
Kim
I R
IR
Fisher