Flux pinning, specific heat and magnetic properties of the laves phase superconductor CeRu<sub>2</sub>
作者:A D Huxley、C Paulson、O Laborde、J L Tholence、D Sanchez、A Junod、R Calemczuk
DOI:10.1088/0953-8984/5/41/018
日期:1993.10.11
A sharp transition from reversible behaviour to irreversible behaviour in the superconducting mixed state of single-crystal samples of CeRu2 is described. Magnetization, AC susceptibility, resistivity and specificheat measurements under an applied field are reported. The results are discussed in relation to conventional models and those of more novel superconductivity, such as the Fulde-Ferrel state
Electronic structure of Ce and its intermetallic compounds
作者:J. C. Fuggle、F. U. Hillebrecht、Z. Zołnierek、R. Lässer、Ch. Freiburg、O. Gunnarsson、K. Schönhammer
DOI:10.1103/physrevb.27.7330
日期:——
Transition to nonmagnetic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>f</mml:mi></mml:math>states in Ce intermetallic compounds studied by bremsstrahlung isochromat spectroscopy
作者:F. U. Hillebrecht、J. C. Fuggle、G. A. Sawatzky、M. Campagna、O. Gunnarsson、K. Schönhammer
DOI:10.1103/physrevb.30.1777
日期:——
X-ray Absorption Near Edge Structure of Amorphous Ce<sub><i>x</i></sub>Ru<sub>100-<i>x</i></sub>
We report the x-ray absorption near edge structure at the Ce L-3 edge for amorphous alloys CexRu100-x (x = 9, 43, and 80) and a C15 Laves phase compound CeRu2, which consists of a couple of peaks characteristic of 4f(1) and 4f(0) configurations. This indicates that Ce atoms of these materials are in a mixed valence state. The spectra are fitted to one arctangent and two Lorentzian functions. The Ce valence estimated from relative areas of the Lorentzian peaks varies linearly with Ce content. The transition into the continuum along with both peaks shifts to lower energy with increasing Ce concentration. We find a linear relation between the transition energy and the valence.
Reentrant Superconductivity of CeRu<sub>2</sub>
作者:Katsuma Yagasaki、Masato Hedo、Takao Nakama
DOI:10.1143/jpsj.62.3825
日期:1993.11.15
Magnetization curves [MC] and temperature dependence of the AC susceptibility [TS] were measured in the superconducting phase of CeRu2 with T(c) = 6.55 K in zero field. For fields higher than 0.8 T in [TS], the superconducting susceptibility behaves normally up to the lowest transition temperature T(cL) where it decreases suddenly; the field-induced reentrant superconductivity occurs at T(cL) and breaks very sharply to the normal state at T(cH) (the highest transition temperature). In [MC], an anomaly appears when the magnetization reaches to the extrapolated magnetization of the normal state at H(R) (reentrant field). Magnetization drops suddenly to negative in the field-increasing process for temperatures below 3.9 K, and it only increases for temperatures above 4.0 K. Reentrant superconductivity occurs between, H(R) and H(c2). The reentrant phase has positive magnetization in the background.