Depth profiles of absorbed hydrogen introduced by electrochemical charging and light elements were analyzed in Ni-Nb-Zr-H amorphous alloy ribbons using a glow discharge optical emission spectrometer. It was clarified ...Depth profiles of absorbed hydrogen introduced by electrochemical charging and light elements were analyzed in Ni-Nb-Zr-H amorphous alloy ribbons using a glow discharge optical emission spectrometer. It was clarified that the absorbed hydrogen was comparatively well-distributed on the sample surface and that the content of the hydrogen decreased with increasing depth from the surface. That is, the amount of absorbed hydrogen on the surface was about 17 at %, while that inside the specimens decreased to several atomic percent. The depth profiles of the hydrogen which were close to the surface were slightly different between those on the roller side and those on the free side in the melt-spun ribbon. The difference is thought to originate from the existence of oxygen impurity on the surface and from the difference of the Zr content.展开更多
The electrical transport properties of (Ni0.8Nb0.2)100-xZrx (x = 30, 40 and 50) amorphous ribbons and hydrogen charged specimens were investigated. The amorphous ribbons indicated a negative coefficient in the tempera...The electrical transport properties of (Ni0.8Nb0.2)100-xZrx (x = 30, 40 and 50) amorphous ribbons and hydrogen charged specimens were investigated. The amorphous ribbons indicated a negative coefficient in the temperature dependence of their electrical resistivity as well as the typical transport properties of the amorphous alloys with comparatively high values of electrical resistivity, ρ. The normalized temperature coefficient of the resistivity (TCR ≡ 1/ρ300K·dρ/dT) tended to increase with increasing x in the temperature range of 100-300 K. These behaviors would suggest that the transport properties of the present amorphous ribbons were governed by temperature variation of the Debye-Waller factor, not by electron-phonon scattering. The hydrogen charged ribbons obtained by an electrochemical method also showed similar electrical resistivity behaviors as a function of the temperature. However, TCR of x = 40 with hydrogen charged ribbon, in which the amount of absorbed hydrogen was about 14 at%, increased about three times more than that of the pre-charged amorphous ribbon.展开更多
文摘Depth profiles of absorbed hydrogen introduced by electrochemical charging and light elements were analyzed in Ni-Nb-Zr-H amorphous alloy ribbons using a glow discharge optical emission spectrometer. It was clarified that the absorbed hydrogen was comparatively well-distributed on the sample surface and that the content of the hydrogen decreased with increasing depth from the surface. That is, the amount of absorbed hydrogen on the surface was about 17 at %, while that inside the specimens decreased to several atomic percent. The depth profiles of the hydrogen which were close to the surface were slightly different between those on the roller side and those on the free side in the melt-spun ribbon. The difference is thought to originate from the existence of oxygen impurity on the surface and from the difference of the Zr content.
文摘The electrical transport properties of (Ni0.8Nb0.2)100-xZrx (x = 30, 40 and 50) amorphous ribbons and hydrogen charged specimens were investigated. The amorphous ribbons indicated a negative coefficient in the temperature dependence of their electrical resistivity as well as the typical transport properties of the amorphous alloys with comparatively high values of electrical resistivity, ρ. The normalized temperature coefficient of the resistivity (TCR ≡ 1/ρ300K·dρ/dT) tended to increase with increasing x in the temperature range of 100-300 K. These behaviors would suggest that the transport properties of the present amorphous ribbons were governed by temperature variation of the Debye-Waller factor, not by electron-phonon scattering. The hydrogen charged ribbons obtained by an electrochemical method also showed similar electrical resistivity behaviors as a function of the temperature. However, TCR of x = 40 with hydrogen charged ribbon, in which the amount of absorbed hydrogen was about 14 at%, increased about three times more than that of the pre-charged amorphous ribbon.
