Superspin-glass nature of discontinuous Co₈₀Fe₂₀/Al₂O₃ multilayers

Authors

• Sarbeswar Sahoo, Laboratorium fu¨r Angewandte Physik, Gerhard-Mercator-Universita¨t Duisburg, D-47048 Duisburg, GermanyFollow
• O. Petracic, Laboratorium fu¨r Angewandte Physik, Gerhard-Mercator-Universita¨t Duisburg, D-47048 Duisburg, Germany
• Christian Binek, University of Nebraska-LincolnFollow
• Wolfgang Kleemann, Laboratorium fu¨r Angewandte Physik, Gerhard-Mercator-Universita¨t Duisburg, D-47048 Duisburg, GermanyFollow
• J.B. Sousa, IFIMUP, Departamento de Fisica, Universidade de Porto, 4169-007 Porto, Portugal
• Susana Cardoso de Freitas, INESC, Rua Alves Redol 9-1, 1000 Lisbon, PortugalFollow
• P.P. Freitas, INESC, Rua Alves Redol 9-1, 1000 Lisbon, Portugal

Document Type

Article

Date of this Version

3-13-2002

Comments

Published by American Physical Society. © 2002. Permission to use. Phys. Rev. B 65, 134406 (2002).

Abstract

Ferromagnetic single domain particles of CoFe in discontinuous magnetic multilayers [Co₈₀Fe₂₀ (0.9 nm)/ Al₂O₃(3 nm)] ₁₀ reveal spin-glass ordering below T_g=43.6 K as evidenced by the criticality of the nonlinear susceptibility. Dynamic critical scaling yields exponents zν=8.0 and β=1.0 in both zero and weak applied field, where an Almeida-Thouless line is encountered. In fields exceeding 2 mT a crossover into a chiral glass regime seems to occur.