Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron diffraction study of average and local structure in
  La0.5Ca0.5MnO3   We used neutron powder diffraction to obtain the local and long-range
structure of La0.5Ca0.5MnO3 at room temperature and 20K. By combining Rietveld
and pair distribution function analysis of the total neutron scattering data,
we have analyzed the structure of the compound using two competing models
describing the low temperature phase: first the charge ordered/orbital ordered
model and second the Mn-Mn dimer model. These structural models fit the 20K
neutron powder diffraction pattern equally well using Rietveld analysis.
Therefore, pair distribution function analysis is used to probe the local and
medium-range structure revealing a system with two distinctly distorted Mn
octahedra and Mn ions with non-integral valence states. The distorted octahedra
differ with the structural model for the Zener polaron type Mn-Mn dimer picture
proposed for Pr0.6Ca0.4MnO3 and order in a similar checkerboard configuration
associated with the CE-type anti-ferromagnetic structure. Therefore, locally
the charge difference and structural ordering between the two Mn is appreciable
enough to describe the system at 20K as "partially charge ordered".

8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
2
The categories of this paper are: math
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an