Cascade of bulk magnetic phase transitions in NaxCoO2 as studied by muon spin rotation.
Using muon spin rotation, well-defined bulk approximately 100% magnetic phases in NaxCoO2 are revealed. A novel magnetic phase is detected for x=0.85 with the highest transition temperature ever observed for x>or=0.75. This stresses the diversity of x>or=0.75 magnetic phases and the link between magnetic and structural degrees of freedom. For the charge-ordered x=0.50 compound, a cascade of transitions is observed below 85 K. From a detailed analysis of our data, we conclude that the ordered moment varies continuously with temperature and suggest that the two secondary transitions at 48 and 29 K correspond to a moderate reorientation of antiferromagnetically coupled moments.
Mendels
P
P
Laboratoire de Physique des Solides, UMR 8502, Université Paris-Sud, 91405 Orsay, France.
Bono
D
D
Bobroff
J
J
Collin
G
G
Colson
D
D
Blanchard
N
N
Alloul
H
H
Mukhamedshin
I
I
Bert
F
F
Amato
A
A
Hillier
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AD