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Cation Distribution, Short‐Range Order and Small Polaron Hopping Conduction in Nickel Manganites, from a Neutron Diffraction Study
Author(s) -
Elbadraoui E.,
Baudour J. L.,
Leroux C.,
Fritsch S.,
Bouree F.,
Gillot B.,
Rousset A.
Publication year - 1999
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199903)212:1<129::aid-pssb129>3.0.co;2-t
Subject(s) - neutron diffraction , crystallography , nickel , octahedron , chemistry , manganite , spinel , ion , materials science , crystal structure , physics , condensed matter physics , ferromagnetism , metallurgy , organic chemistry
Abstract By means of neutron diffraction, a study has been made of the variation of the cationic distribution and short‐range order in nickel‐manganite ceramics Ni 0.8 Mn 2.2 O 4 , in relation with their thermal history. The thermal treatment of metallization which is an annealing at 850 °C followed by a quenching, induces a partial migration of Ni 2+ ions from octahedral B to tetrahedral A sites of the cubic spinel structure and a decrease of the short‐range order between nickel and manganese atoms on the B sites. These two effects increase the probability of the hopping of electrons from octahedral‐site Mn 3+ to octahedral‐site Mn 4+ and provide the major mechanism for the electrical conductivity increase associated with the thermal treatment of metallization of ceramics.