Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The effect of grain boundaries on the domain wall dynamics in
  Pr$_{1-x}$Ag$_x$MnO$_3$ manganites   We performed detailed ac susceptibility measurements on
Pr$_{1-x}$Ag$_x$MnO$_3$ ($x$=0.15, 0.20) manganites and observed unusual and
interesting features, which are associated with the domain walls and the
effects of grain-boundaries on their movements. It is shown that the ac field,
frequency, temperature, thermal cycling and grain coupling significantly
influence the real and especially imaginary parts of the ac susceptibility. We
argue that the cooperative depinning of the domain walls from the
grain-boundaries accompanying with a large distance movements of the walls
leads to the appearance of an anomaly at low temperatures. The anomaly is
observed above a threshold ac field and depends on the intergrain coupling. The
results show that in the powdered form of bulk samples, the anomaly disappears
and the ac field dependence of the $\chi'$ and $\chi"$ suppresses. Below the
anomaly temperature, significant and unusual thermal hysteresis occurs in the
real and especially imaginary parts of the ac susceptibility. Thermal
hysteresis depends on the thermal cycling and indicates thermally irreversible
wall pinning and depinning. The susceptibility is practically
frequency-independent in the temperature range of thermal hysteresis i.e. below
the anomaly. The frequency dependence of ac susceptibility between the anomaly
temperature and the transition temperature is discussed by considering the
temperature dependence of the relaxation process of the domain walls.

0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph