AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeM

Paper MI-WeM6
Exploring New Magnetic Properties in Coupled Magnetic Nanostructures

Wednesday, November 17, 2004, 10:00 am, Room 304A

Session: Magnetic Nanostructures
Presenter: C. Won, University of California at Berkeley
Authors: C. Won, University of California at Berkeley
Y.Z. Wu, University of California at Berkeley
A. Scholl, Lawrence Berkeley National Laboratory
A. Doran, Lawrence Berkeley National Laboratory
N. Kurahashi, University of California at Berkeley
H. Zhao, 3 International Center for Quantum Structures, China
Z.Q. Qiu, University of California at Berkeley
Correspondent: Click to Email
Interaction between different magnetic entities in a magnetic nanostructure creates new properties that are not available in single phase bulk materials. In order to study how the magnetic interaction at nanometer scale generates new magnetic behaviors, we applied photoemission electron microscopy (PEEM) to investigate coupled magnetic nanostructures. The unique element-specific capability of PEEM allows the measurement of different magnetic species separately, thus enabling the identification of new magnetic properties caused the magnetic coupling. Several systems have been investigated by our group in the last a few years. In this talk, I will first give an overview of the research topics that we studied using PEEM. Then I will focus on a particular topic of magnetic phase transition in coupled magnetic layers. Co/Cu/Ni/Cu(100) and Co/Fe/Ni/Cu(100) are fabricated using epitaxial growth in which the Cu and Fe spacer layers controls the interlayer coupling between Co and Ni films. Element-specific measurements are performed to monitor the ferromagnetic to paramagnetic phase transitions of the Co and Ni films separately. Our results show that the interlayer coupling couples the magnetic fluctuations of the Co and Ni films to result in three types of magnetic phase transitions. A complete phase diagram is constructed in the Co-Ni thickness plane and a Monte Carlo simulation explains the conditions of having these three types of transitions.