Magnetoresistance and efficiency measurements of indium tin oxide/N , NЈ-diphenyl-N , NЈ bis͑3-methylphenyl͒-͑1,1Ј-biphenyl͒-4,4Ј diamine/aluminum tris͑8-hydroxyquinoline͒/cathode organic lightemitting diode structures have been made as a function of magnetic field and cathode type. It has been found that magnetoresistance occurs only when there is light emission from the devices, which suggests that the magnetoresistance is related to exciton formation. Comparison of the effects of applied field on device efficiency and magnetoresistance shows that the magnetoresistance cannot be due to the recombination current. We suggest that the effect may be due to trapping of charge carriers at triplet excitons within the device.

This topical review discusses magnetic microelectromechanical systems (MagMEMS). A number of exemplars are drawn from the authors' own work, and a review is given of other significant literature in the area. The case is made that MagMEMS offer unique features over conventional MEMS, such as remote interrogation and self-test. A review of the key magnetic principles and magnetic materials is included by way of a guide to the general reader. Finally, a roadmap for the future development of MagMEMS is set out.

The magnetoresistance (MR) of organic spin valves containing the spacer layer regioregular poly(3-hexylthiophene) (RR-P3HT), which is a conjugated polymer, has been studied at room temperature. Investigations have been made of the influence of the thickness of organic spacer layer on the magnetoresistance of Fe50Co50∕RR-P3HT∕Ni81Fe19 spin valves. It was determined that the MR decreased as the layer thickness increased, consistent with the spin coherence length in this material. It has been observed at room temperature that there is the co-occurrence of two magnetoresistance effects, the spin-valve magnetoresistance, and anisotropic magnetoresistance in the magnetic electrodes.

No abstract

Amorphous melt spun ribbon samples of Fe61Co10Zr5W4B20 alloy of various thicknesses up to ∼350 μm and suction cast 1 mm diameter rod and 2, 3, and 4 mm outside diameter tube samples of the same alloy were produced. The experimental results for the rod samples indicate a relatively high saturation polarization μ0Ms=0.8 T and a Curie temperature TC=615 K, as well as a very low coercive field Hc=1.4±0.5 A/m with high anisotropy that lowers the permeability of the samples. Thermal analysis by differential scanning calorimetry carried out on ribbon and rod samples revealed a large supercooled liquid region ΔTx of ∼60 K for this alloy.