Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Series of Bulk Magnetic Phase Transitions in NaxCoO2: a muSR study   Using muon spin rotation, well-defined bulk ~ 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 >= 0.75. This stresses the diversity
of x >=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 K and 29 K correspond to a
moderate reorientation of antiferromagnetically coupled moments.

31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int