Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of the rare earth effects on the magnetic fluctuations in
  RbLn$_2$Fe$_4$As$_4$O$_2$ (Ln = Tb, Dy and Ho) by M\"ossbauer spectroscopy   In the current work, we report the investigation of RbLn$_2$Fe$_4$As$_4$O$_2$
(Ln = Tb, Dy and Ho) and RbFe$_2$As$_2$ by $^{57}$Fe M\"ossbauer spectroscopy.
Singlet pattern has been observed for all the samples indicating the absence of
static magnetic ordering down to 5.9\,K on the Fe sublattice. The observed
intermediate value of the isomer shift confirms the effective self charge
transfer effect for the studied superconductors. Debye temperatures of these
samples have been determined by the temperature dependence of the isomer shift.
Most importantly, we observe different spectral line width broadening behaviors
for samples with different rare earth elements, and no line width broadenings
for samples Ln=Tb and Ho. These results suggest that the observed magnetic
fluctuations at the Fe site might be sensitive to the magnetic behaviors of the
rare earth magnetic moments.

17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio