J. Phys. IV France 12 (2002) Pr9-351
DOI: 10.1051/jp4:20020435

Electron paramagnetic resonance in the quasi-two dimensional magnetic ludwigite Fe ₃O ₂BO ₃

J. Dumas¹, J.L. Tholence¹, M. Continentino², J.C. Fernandes², R.B. Guimaraes² and M.H. Whangbo<sup>3

1</sup>  Laboratoire d'Études des Propriétès Électroniques des Solides, CNRS, BP. 166, 38042 Grenoble cedex 9, France
²  Instituto de Fisica, Universidade Federal Fluminense, Niteroi 21210-340 RJ, Brazil
³  North Carolina State University, Raleigh, NC 27695-8204, U.S.A.

Abstract
We report an EPR study of the quasi-two dimensional oxide Fe ₃O ₂BO ₃ which shows a structural transition at 283 K, an antiferromagnetic transition at 112K and weak ferromagnetism below 73 K. The single crystals show three strongly anisotropic lines with different temperature dependences of their widths and resonance fields. The results are discussed in relation with the different phase transitions and with the Wigner glass phase which appears between ~112 K and ~200 K.

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