Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetocaloric effect in
  {[Fe(pyrazole)$_4$]$_2$[Nb(CN)$_8$]$\cdot$4H$_2$O}$_n$ molecular magnet   Magnetocaloric effect in
{[Fe(pyrazole)$_4$]$_2$[Nb(CN)$_8$]$\cdot$4H$_2$O}$_n$ molecular magnet is
reported. It crystallizes in tetragonal I4$_1$/a space group. The compound
exhibits a phase transition to a long range magnetically ordered state at
$T_\mathrm{c}\approx$8.3 K. The magnetic entropy change $\Delta S_\mathrm{M}$
as well as the adiabatic temperature change $\Delta T_\mathrm{ad}$ due to
applied field change $\mu_0\Delta H$=0.1, 0.2, 0.5, 1, 2, 5, 9 T as a function
of temperature have been determined by the relaxation calorimetry measurements.
The maximum value of $\Delta S_\mathrm{M}$ for $\mu_0\Delta H=5$ T is 4.9 J
mol$^{-1}$ K$^{-1}$ (4.8 J kg$^{-1}$ K$^{-1}$) at 10.3 K. The corresponding
maximum value of $\Delta T_\mathrm{ad}$ is 2.0 K at 8.9 K. The temperature
dependence of the exponent $n$ characterizing the field dependence of $\Delta
S_\mathrm{M}$ has been estimated. It attains the value of 0.64 at the
transition temperature, which is consistent with the 3D Heisenberg universality
class.

21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess