Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometric frustration on the trillium lattice in a magnetic
  metal-organic framework   In the dense metal-organic framework Na[Mn(HCOO)$_3$], Mn$^{2+}$ ions
($S=\frac{5}{2}$) occupy the nodes of a `trillium' net. We show that the system
is strongly magnetically frustrated: the N\'eel transition is suppressed well
below the characteristic magnetic interaction strength; short-range magnetic
order persists far above the N\'eel temperature; and the magnetic
susceptibility exhibits a pseudo-plateau at $\frac{1}{3}$-saturation
magnetisation. A simple model of nearest-neighbour Heisenberg antiferromagnetic
and dipolar interactions accounts quantitatively for all observations,
including an unusual 2-$\mathbf k$ magnetic ground-state. We show that the
relative strength of dipolar interactions is crucial to selecting this
particular ground-state. Geometric frustration within the classical spin liquid
regime gives rise to a large magnetocaloric response at low applied fields that
is degraded in powder samples as a consequence of the anisotropy of dipolar
interactions.

17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess