Morin transition in Hematite nanoparticles analyzed by neutron diffraction

7th Meeting of the Spanish Neutron Scattering Association

Pérez-Landazábal, J.I.^1 ; Gómez-Polo, C.^1 ; Recarte, V.^1 ; Larumbe, S.^1 ; Sánchez-Alarcos, V.^1 ; Silva, M Fernandes^2 ; Pineda, E A Gómez^2 ; Hechenleitner, A A Winkler^2 ; Lima, M.K.^2 ; Rodriguez-Velamazán, J.A.^3,4

Departamento de Física, Universidad Pública de Navarra, Campus de Arrosadía, Pamplona

31006, Spain^1

Departamento de Química, Universidade Estadual de Maringá, Maringá- PR

87020-900, Brazil^2

Instituto de Ciencia de Materiales de Aragón, CSIC, Universidad de Zaragoza, Zaragoza, Spain^3

Institut Laue-Langevin, CRG's D1B, Grenoble

F-38042, France^4

关键词: Applied magnetic fields;    Bulk materials;    Bulk samples;    Diffraction spectra;    Hematite nanoparticles;    Mean particle size;    Morin transitions;    Spin reorientation transitions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/663/1/012003/pdf
DOI  :  10.1088/1742-6596/663/1/012003

来源: IOP

【 摘 要 】

Hematite (α-Fe2O3) undergoes a first order spin reorientation transition called the Morin transition: upon cooling, the moments align antiferromagnetically along the rhombohedral axis, and the net magnetic moment goes to zero. Morin transition temperature is around to 260K in bulk materials and depends on the mean particle size. In this work, the Morin transition has been studied by neutron diffraction as function of temperature and applied magnetic field in 47 nm nanoparticles. The Rietveld analysis of the diffraction spectra around the Morin transition shows a similar behavior to that found in bulk samples. On the other side, the magnetic field induced phase transformation has been analyzed.