Nature of the transition between a ferromagnetic metal and a spin-glass insulator in pyrochlore molybdates.
The metal-insulator transition has been investigated for pyrochlore molybdates R(2)Mo(2)O(7) with nonmagnetic rare-earth ions R. The dynamical scaling analysis of ac susceptibility reveals that the geometrical frustration causes the atomic spin-glass state. The reentrant spin-glass phase exists below the ferromagnetic transition. The electronic specific heat is enhanced as compared to the band calculation result, perhaps due to the orbital fluctuation in the half-metallic ferromagnetic state. The large specific heat is rather reduced upon the transition, likely because the short-range antiferromagnetic fluctuation shrinks the Fermi surface.
Hanasaki
N
N
Department of Applied Physics, University of Tokyo, Tokyo, Japan.
Watanabe
K
K
Ohtsuka
T
T
Kézsmárki
I
I
Iguchi
S
S
Miyasaka
S
S
Tokura
Y
Y
D005898:Glass; D059346:Magnets; D008670:Metals; D008956:Models, Chemical; D044366:Transition Temperature
D008670:Metals