Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vacancy defects and monopole dynamics in oxygen-deficient pyrochlores   The idea of magnetic monopoles in spin ice has enjoyed much success at
intermediate temperatures, but at low temperatures a description in terms of
monopole dynamics alone is insufficient. Recently, numerical simulations were
used to argue that magnetic impurities account for this discrepancy by
introducing a magnetic equivalent of residual resistance in the system. Here we
propose that oxygen deficiency is the leading cause of magnetic impurities in
as-grown samples, and we determine the defect structure and magnetism in
Y2Ti2O(7-\delta) using diffuse neutron scattering and magnetization
measurements. These defects are eliminated by oxygen annealing. The
introduction of oxygen vacancies causes Ti4+ to transform to magnetic Ti3+ with
quenched orbital magnetism, but the concentration is anomalously low. In the
spin-ice material Dy2Ti2O7 we find that the same oxygen-vacancy defects
suppress moments on neighbouring rare-earth sites, and that these magnetic
distortions dramatically slow down the long-time monopole dynamics at
sub-Kelvin temperatures.

9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int