Magnetic Properties of h.c.p. Fe-Ru Alloys

X-ray diffraction experiments at room temperature and magnetization measurements from 4.2 to about 1000°K have been performed on the whole composition range of Fe-Ru alloys. The magnetic susceptibility, χ, in the ε phase of 100 at% Ru to 13 at% Ru-Fe alloy shows a Pauli-paramagnetic temperature dependence at high temperatures with small negative and positive temperature coefficients for the alloys less than and more than 30 at% Ru, respectively. The value of χ at room temperature increases with increasing Fe concentration from 100 at% Ru ; the extrapolated value of χ, that is χ of the ε Fe, is as large as 10^/Oe/mole. The Fe-rich alloys in the ε phase shows some decrease in χ at low temperatures, suggesting the occurrence of metallic antiferromagnetic ordering. The reason for the variation in χ with Fe concentration may be attributed to the change in the density of states at the Fermi level due to the change of the width of the d-band, relative position of the Fermi level being unchanged because of the fixed number of outer electrons

Study on a New Train Control System in the IoT Era: From the Viewpoint of Safety2.0

Safety2.0 which advocates cooperative safety is attracting attention. Assuming that Industry4.0 proposed by the German authorities is an IoT-based production revolution, Safety2.0 is a Japanese-originated proposal that seeks to create a more flexible and sophisticated safety by introducing Internet of Things (IoT) into production sites. This chapter introduces the concepts of Safety2.0 and its spread internationally, focusing on the activities of IGSAP, a Safety2.0 promoter. Furthermore, we look back on the conventional train control from the viewpoint of Safetyx.x and look at the appearance of the train control suitable for Safety2.0 using IoT. As a result, in this chapter, we propose a simple and smart train control system unified train control system (UTCS), in which a train control system is realized in a hierarchical structure of a logic layer, a network layer, and a terminal layer, and discuss its processing method

On the Magnetic and Electric Properties of (Fe_<1-x>Co_x)_<0.89>Cr_<0.11> Alloys

To make clear the mechanism of the appearance of large spontaneous volume magnetostriction of fcc (Fe_Co_x)_Cr_ alloys, their magnetization and elctrical resistivity were measured and the following results were obtained : (1) The dependences of the mean magnetic moments and the Curie point on the concentration, x, and the outer electron concentration, n, of the alloys were similar to those in the Fe-Ni and Fe-Pd Invar alloy systems. That is, the alloys in these three systems are ferromagnetic on the Co- and Ni-rich sides and their ferromagnetic moments disappeared at the n of about 8.2～8.4 which corresponds to the concentration containing Fe more than it in Invar alloys. (2) The magnetization-temperature curve of the Invar alloys mentioned above did not follow Brillouin\u27s function. (3) The electrical resistivity-temperature curves of the Invar alloys showed an anomalous broad maximum near the Curie point. And the residual resistivity were very large. These phenomena may be explained by the co-existence of the ferromagnetic and antiferromagnetic states. It may be considered that the co-exsistence of the two magnetic states is closely connected with the sharp drop of the ferromagnetic moments near the concentration of Invar type alloys

Magnetic Domain Structure of an Amorphous Fe-P-C Alloy

The domain structure of an amorphous Fe_P_C_7 alloy ribbon produced by the centrifugal solidification technique was investigated using the magnetic powder pattern technique. Two different types of domains (a maze domain and a 180°-domain) were observed on the specimen surface. The relationship between the domain structure and the magnetization process was also investigated. The results showed that some of the 180°-walls, which ran nearly parallel to the long axis of the ribbon, caused the hysteresis in the magnetization curve, while the maze domain was responsible for the difficulty in obtaining the saturation in magnetization. The maze domain arises probably from the uniaxial magnetic anisotropy having the direction of easy magnetization perpendicular to the surface. This anisotropy seems to be caused by the magnetoelastic coupling between positive magnetostriction and internal stress in the specimen