Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magneto-optical and magnetotransport properties of heavily Mn-doped
  GaMnAs   We have studied the magneto-optical and magnetotrasnport properties of GaMnAs
thin films with high Mn concentrations (x= 12.2 - 21.3%) grown by
molecular-beam epitaxy. These heavily Mn-doped GaMnAs films were formed by
decreasing the growth temperature to as low as 150-190 degree C and by reducing
the film thickness to 10 nm in order to prevent precipitation of hexagonal MnAs
clusters. Magnetic circular dichroism (MCD) and anomalous Hall effect
measurements indicate that these GaMnAs films have the nature of intrinsic
ferromagnetic semiconductors with high ferromagnetic transition temperature up
to 170 K.

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The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs