Artigo
Ferrimagnetism and spin excitation in a Ni-Mn partially inverted spinel prepared using a modified polymeric precursor method
Registro en:
Materials Chemistry And Physics. Lausanne: Elsevier Science Sa, v. 146, n. 1-2, p. 58-64, 2014.
0254-0584
10.1016/j.matchemphys.2014.02.042
WOS:000336467900008
1353862414532005
0000-0002-7734-4069
Autor
Ferreira, Rafael A. [UNESP]
Tedesco, Julio C. G.
Birk, Jonas O.
Kalceff, Walter
Yokaichiya, Fabiano
Rasmussen, Nina
Pena, Octavio
Henry, Paul F.
Simeoni, Giovanna G.
Bordallo, Heloisa N.
Lisboa Filho, Paulo Noronha [UNESP]
Resumen
We demonstrate that a Ni-Mn oxide partially inverted spinel (Ni1-pMnv)[NivMn2-v]O-4 having inversion degree v approximate to 0.8 and produced by a modified polymeric precursor method exhibits behaviour previously reported only in monophased samples. The structure of the specimen was determined using Rietveld analysis of X-ray and neutron powder diffraction data, showing that at room temperature the material crystallizes in the Fd3(over bar)m space group with a lattice constant a = 8.392 angstrom. Combining magnetization measurements with neutron powder diffraction, we show that the magnetic structure of this spinel is associated with the interplay between the ferromagnetic and antiferromagnetic lattices which coexist due to the cations' presence on both tetrahedral and octahedral sites. Our analysis of the neutron diffraction data confirms the postulated magnetic structure involving a star-like moment arrangement, arising from competition for the B (octahedral) spinel sites by the Ni and Mn cations. Finally, we show that strong magnetic fluctuations are observed in the inelastic neutron scattering data. (C) 2014 Elsevier B.V. All rights reserved. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) NR HNB Univ Estadual Paulista, Fac Ciencias, Programa Posgrad Ciencia & Tecnol Mat POSMAT, BR-17033360 Sao Paulo, Brazil Univ Rennes 1, Inst Sci Chim Rennes UMR 6226, F-35042 Rennes, France Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark Univ Technol Sydney, Sch Phys & Adv Mat, Broadway, NSW 2007, Australia Lab Nacl Luz Sincrotron, BR-13083970 Campinas, SP, Brazil Comissao Nacl Energia Nucl, Inst Pesquisas Energet & Nucl, Reactor Multiproposito Brasileiro, Sao Paulo, Brazil European Spallat Source ESS AB, S-22100 Lund, Sweden Tech Univ Munich, Heinz Maier Leibnitz Zentrum MLZ, D-85748 Garching, Germany Tech Univ Munich, Dept Phys, D-85748 Garching, Germany Univ Estadual Paulista, Dept Fis, Fac Ciencias, BR-17033360 Sao Paulo, Brazil Univ Estadual Paulista, Fac Ciencias, Programa Posgrad Ciencia & Tecnol Mat POSMAT, BR-17033360 Sao Paulo, Brazil Univ Estadual Paulista, Dept Fis, Fac Ciencias, BR-17033360 Sao Paulo, Brazil CNPq: 706/11