From A-type antiferromagnetism to ferromagnetism in half-doped perovskite manganites

• Published in: Journal of magnetism and magnetic materials Vol. 270; no. 1; pp. 194 - 202
• Main Authors: Autret, C, Martin, C, Hervieu, M, Maignan, A, Raveau, B, André, G, Bourée, F, Jirak, Z
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2004; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetism; Manganites; Neutron diffraction; Phase separation; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); 75.25.+z; 61.66.Fn; Magnetism; Neutron diffraction; Phase separation; Manganites; Antiferromagnetism; Temperature dependence; Inorganic compounds; Electrical conductivity; Curie point; Magnetization; Transition element compounds; Doping; 61.66.Fn Manganites; Perovskites; Experimental study; Ferromagnetism; Quaternary compounds
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2003.08.018

We have studied by neutron diffraction, resistivity and magnetization measurements the variation of the structural, magnetic and electric properties as a function of the cation size mismatch at the perovskite A-site. The four selected compounds RE 0.5AE 0.5MnO 3, with extremely large A-site cation size 〈 r A〉=1.25–1.28 Å, correspond to two 〈 r A〉 values and for each 〈 r A〉, two mismatch values have been retained. This study shows that the decrease of σ 2 is an essential factor in stabilization of the ferromagnetism. As a result, the Curie temperature is markedly increased for the samples with smaller σ 2, even if they exhibit a complex ferromagnetic/antiferromagnetic phase-separated state at low temperature.