Supplementary material
Jahn-Teller assisted polaron hopping and associated dielectric response of
PrFe0.5Mn0.5O2.95
C. Ganeshraj1, S. Kavita2, R. Mahendiran2, Neetika Sharma3, A. Das3, and P.N. Santhosh1,*
1
Low temperature Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600
036, India.
2
Department of Physics, Faculty of Science, 2 Science Drive 3, National University of Singapore, Singapore.
3
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
The polycrystalline sample PrFe0.5Mn0.5O2.95 (PFMO) crystallize in an orthorhombically
distorted perovskite structure (Pnma space group) with the octahedral tilt system a- b+ a- (Glazer’s
notation). For refinement, a Pseudo-Voigt function was chosen to generate the line shape of the
diffraction peaks. The background was fitted with linear interpolation method. All the magnetic
peaks could be indexed with k=0 which reflects that the magnetic and chemical cell are identical.
The magnetic structure was refined by using the representation analysis of magnetic structures
for Pnma [1] in BASIREPS program [2]. The refined structural parameters derived from neutron
diffraction patterns measured at 300K and 5 K are listed in table I and refined patterns are shown
in figures I (a) and I (b). The magnetic structure of PFMO is shown in the inset of figure I (a).
We find that the Pr3+ moments do not order magnetically down to 5 K. Canted antiferromagnetic
behaviour can arise due to DM ineraction as well as single ion anisotropy.
FIG I: Rietveld refinement of the neutron diffraction data of PFMO (a) 300 K and (b) 5 K. Inset
of (a) shows the magnetic structure of PFMO obtained from refinement. Blue balls indicate
Fe/Mn-ions with the spin direction. For clarity, oxygen and Pr ions are not shown.
Table
Table I: Result of refinement of Neutron diffraction data at 300 K and 5 K. Lattice constants,
volume, bond lengths, bond angles and magnetic moments along b and c axis are given in their
respective units.
PFMO
300 K
5K
a (Å)
5.5551 (1)
5.5632 (6)
b (Å)
7.7539 (1)
7.7262 (8)
c (Å)
5.4751 (1)
5.4651 (6)
V (Å3)
235.84
234.94
Mn/Fe-O11 x 2 (Å)
1.983 (1)
1.978 (1)
Mn/Fe-O22 x2 (Å)
2.020 (5)
2.037 (4)
Mn/Fe-O22 x2 (Å)
1.987 (5)
1.970 (4)
Mn/Fe-O11-Mn/Fe (°)
155.54 (7)
155.02 (6)
Mn/Fe-O22-Mn/Fe (°)
153.45 (1)
153.36 (1)
M (μB) on Mn (along b)
3.028
4.101
M (μB) on Mn (along c)
2.287
2.088
Rp (%)
4.39
4.73
Rwp (%)
5.65
6.07
χ2
1.19
1.23
References
[1]. Bertaut E F, Acta Crystallogr. A 24, 217 (1968).
[2]. J. Rodriguez-Carvajal, Physica B, 192, 55 (1993).