The negative magnetoresistance of Fe/Tb magnetic multilayer

金沢大学理工研究域環境デザイン学系Magnetic twist driven magnetoresistance in Fe/Tb magnetic multilayer is studied. The negative MR ratio is observed to be 24.6 % on [Fe(12 nm)/Tb(15 nm)]25 at 4.2 K, which is much larger than that of Tb monolayer film, 9.9 %. Such large MR has never reported in multilayer systems including rare earth metal. Assuming that the MR of Tb can also be explained by the AMR effect, it means that the MR effects of the Tb layer is enhanced by spin polarization of the Fe layers. © 2009 IOP Publishing Ltd

The enhanced negative magnetoresistance of Fe/Tb multilayer at multiextreme conditions

金沢大学理工研究域環境デザイン学系Magnetoresistance (MR) in Fe/Tb magnetic multilayer is studied under multiextreme conditions, i.e., high magnetic field, low temperature, and high pressure. The negative MR is observed to be 24.6% in [Fe (12 nm) /Tb (15 nm)] 25 at 4.2 K, and MR is not saturated completely even up to 30 T. With increasing pressure, the magnitude of MR tends to be suppressed, indicating that magnetic order in the Tb layers is suppressed by applying pressure. © 2008 American Institute of Physics

Temperature-Responsive One-Dimensional Nanogels Formed by the Cross-Linker-Aided Single Particle Nanofabrication Technique

A single particle nanofabrication technique was successfully applied to the fabrication of homogeneous poly­(<i>N</i>-isopropylacrylamide) (PNIPAAm) 1D nanogels over a large area, using <i>N</i>,<i>N</i>′-methylene-bis-acrylamide (MBAAm) as a cross-linker. The PNIPAAm 1D nanogels with high aspect ratio over 130 were formed uniformly on the substrate, and the mechanical strength and the length of the 1D nanogels can be easily controlled by adjusting the MBAAm content. The 1D nanogels were transformed from the non-aggregated to aggregated forms over a lower critical solution temperature (LCST) of approximately 32 °C in water. Precise trace of the temperature induced change in the size of the 1D nanogel was well interpreted by the coil-to-globule transition of PNIPAAm, which was clearly visualized in the present study. This is the first report of uniform shape change for a 1D nanogel by external stimulus over a large area