Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Saturation magnetization and band gap tuning in BiFeO$_3$ nanoparticles
  via co-substitution of Gd and Mn   In this investigation, Gd and Mn co-doped
Bi$_{0.85}$Gd$_{0.15}$Fe$_{1-x}$Mn$_x$O$_3$ (x=0.0-0.15) nanoparticles have
been prepared to report the influence of co-substitution on their structural,
optical, magnetic and electrical properties. Due to simultaneous substitution
of Gd and Mn in BiFeO$_3$, the crystal structure has been modified from
rhombohedral (R3c) to orthorhombic (Pn21a) and the Fe-O-Fe bond angle and Fe-O
bond length have been changed. For Mn doping up to 10 % in
Bi$_{0.85}$Gd$_{0.15}$Fe$_{1-x}$Mn$_x$O$_3$ nanoparticles, the saturation
magnetization (Ms) has been enhanced significantly, however, for a further
increase of doping up to 15 %, the Ms has started to reduce again. The
co-substitution of Gd and Mn in BiFeO$_3$ nanoparticles also demonstrates a
strong reduction in the optical band gap energy and electrical resistivity
compared to that of undoped BiFeO$_3$.

19
The categories of this paper are: eess
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas