Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low temperature ferromagnetism, surface paramagnetism and exchange bias
  effect in nano-grained alpha-Fe1.4Ga0.6O3 oxide   The compound alpha-Fe1.4Ga0.6O3 has been prepared by mechanical alloying of
alpha-Fe2O3 and Ga2O3 and subsequent heating of the mechanical alloyed samples
in vacuum condition. Magnetic ordering of alpha-Fe2O3 has been modified by
substitution of non-magnetic Ga atoms. The ferromagnetism in alpha-Fe1.4Ga0.6O3
is more soft and enhanced in comparison to alpha-Fe2O3. M\"ossbauer
spectroscopy also confirmed enhanced ferromagnetic order in alpha-Fe1.4Ga0.6O3.
The room temperature soft ferromagnetism by Ga substitution is interesting for
designing alpha-Fe2O3 based unconventional ferromagnet, which is a great
challenge to the materials scientists. The alpha-Fe1.4Ga0.6O3 samples also
exhibited features of exchange bias, low temperature surface paramagnetism, and
suppression of Morin transition. These features have been affected up to
certain extent by the nano-sized grains of the samples.

36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an