40 research outputs found
Experimental studies of strong dipolar interparticle interaction in monodisperse Fe3O4 nanoparticles
No full textInterparticle interaction of monodisperse Fe3 O4 nanoparticles has been experimentally investigated by dispersing the nanoparticles in solvents. With increasing the interparticle distances to larger than 100 nm in a controlled manner, the authors found that the blocking temperature (TB) of the nanoparticles drops continuously and eventually gets saturated with a total drop in TB of 7-17 K observed for 3, 5, and 7 nm samples, compared with their respective nanopowder samples. By carefully studying the dependence of TB on the interparticle distance, the authors could demonstrate that the experimental dependence of TB follows the theoretical curve of the dipole-dipole interaction. © 2007 American Institute of Physics.open313
Large Exchange Bias due to the Spin Density Wave Antiferromagnet Cr in a Fe/Cr(100) Bilayer
No full textThe temperature and cooling-field dependences of an exchange bias field in a 4-nm Fe/16.2-nm Cr(100) bilayer were studied in this work. Unexpectedly, the magnetic hysteresis loop exhibits a large shift, by as much as -100 Oe, at low temperatures below 40 K, which becomes gradually reduced with increasing cooling field and temperature. This large exchange bias results from an interfacial exchange coupling between the remnant Fe moments and the in-plane uncompensated Cr moments. This uncompensated spin density wave in the Cr layer is produced by interface disorders, such as epitaxial strain due to the lattice mismatch between the MgO substrate and the Cr layer and interface roughness. The cooling field possibly decreases the exchange bias due to the transition from the uncompensated spin state to a partially compensated spin state of Cr spins at the interface.Work at Korea
Advanced Institute of Science and Technology (KAIST)
was supported through the Creative Research Institute
Project and the Cavendish-KAIST Cooperation Project
of the Korean Ministry of Science and Technology and
Works at SungKyunKwan University were supported by he BK21 program, the 21st Century Frontier R&D Pro-
gram for Hydrogen Energy and the Basic Atomic Energy
Research Institute program
Influence of substrate heating and annealing on the properties and photoresponse of manganese doped zinc oxide thin films
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Anisotropic Magnetotransport Properties of La0.67Sr0.33MnO3 Thin Film
No full textAbstractWe have deposited La0.67Sr0.33MnO3 (LSMO) thin film on Si substrate and studied the magnetotransport properties of it. The magnetoresistance (MR) of LSMO thin film shows a large MR for current parallel to applied magnetic field compared to current perpendicular to field, which agrees well with the large magnetization observed when the magnetic field applied parallel to plane of the film. The angular dependence of magnetoresistance deviating from the sinusoidal behaviour indicates the role played by grain boundary. From the anisotropic magnetotransport and magnetic measurements, it is evident that our LSMO thin film exhibits the in-plane anisotropy
Synthesis of BiFeO3 thin films by chemical solution deposition – Structural and magnetic studies
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