Effect of Cr Substitution on the Crystal and Magnetic Structure of (Pr0.55Ca0.45)MnO3 |
| Journal |
Advances in Science and Technology (Volume 52) |
| Volume |
Spin Injection and Transport in Magnetoelectronics |
| Edited by |
P. VINCENZINI and D. FIORANI |
| Pages |
93-97 |
| DOI |
10.4028/www.scientific.net/AST.52.93 |
| Online since |
October, 2006 |
| Authors |
A. Martinelli,
M. Ferretti,
Carlo Castellano,
M.R. Cimberle,
M. Tropeano,
C. Mondelli
|
| Keywords |
Magnetic Measurement, Manganites, Neutron Diffraction, Rietveld Refinement |
| Abstract |
The crystal and magnetic structures of (Pr0.55Ca0.45)(Mn1-yCry)O3 (y = 0.00, 0.03, 0.06) have
been investigated between 5 and 300 K by means of neutron powder diffraction followed by Rietveld
refinement and dc magnetic measurements. An orthorhombic-to-monoclinic phase transition occurs on
cooling in (Pr0.55Ca0.45)MnO3; at lower temperature charge ordering in the Mn sub-lattice, coupled with
orbital ordering, induces an anti-ferromagnetic (AFM) spin ordering within the monoclinic phase. Cr
substitution at the Mn site hinders the phase transition, although for the y = 0.03 sample small amounts of
the monoclinic phase co-exist at low temperature with the main phase characterized by an orthorhombic
structure. In addition Cr favours ferromagnetism (FM) participating to the double exchange mechanism. Cr
substitution prevents charge ordering, favouring double exchange and hence FM spin ordering within the
Mn sub-lattice. The Curie temperature of the Cr substituted samples is independent on the Cr content. |
| Full Paper |
Get the full paper by clicking here
|
| Preview |
Free first page example |
