Magnetism and superconductivity inY1−xTbxNi

Abstract

The magnetic and superconducting properties in a series of pseudo-quaternary compounds Y 1Ϫx Tb x Ni 2 B 2 C were investigated by the temperature-dependent magnetization M (T) for applied field parallel and perpendicular to the c axis and by in-plane resistivity, (T). There was a large anisotropy in M (T), which is attributed to the crystalline electric field effects. As the Tb concentration x is increased, the superconducting transition temperature T c decreases and disappears rapidly in the vicinity of xϭ0.4 while the Néel temperature T N appears abruptly near xϭ0.4 and increases with Tb content. In addition, the increase of M (T) at low temperatures below T N was observed for xу0.4, of which the onset temperature T WF is regarded as development of weak-ferromagnetic component. T WF was also in proportion to the Tb content x accompanied by T N . The linear decrease of T c for dilute Tb concentration seems to follow an Abrikosov-Gor'kov expectation, while the sudden destruction of T c near xϭ0.4 seems to have close correlation with the emergence of magnetic states, i.e., antiferromagnetic and weak-ferromagnetic states. Possible scenarios for the correlation are discussed.

A critical examination of room temperature ferromagnetism in transition metal-doped oxide semiconductors

“…From the figure it is recognized that the Co state of Ti 1Àx Co x O 2 is the same as that of CoO, which is high spin Co 2þ ð3d 7 ; S ¼ 3 2 ). To further confirm this conclusion, theoretical model calculations were done for the XAS spectra for both high-and low-spin states in O h symmetry [11], and the results are also plotted in Fig. 1; it is evident that the high-spin calculation reproduces the experimental data well.…”

Magnetic pair breaking and weak ferromagnetism in single crystals ofEr1−xTbxKim1, Cho2 2002Phys. Rev. BSelf Cite6010View full textAdd to dashboardCite

“…In order to understand the magnetic interactions, the T N versus DG values for the single crystalline samples of Y 1Ϫx Tb x Ni 2 B 2 C, 13 and Ho 1Ϫx Dy x Ni 2 B 2 C, 14 are also plotted in Fig. 4.…”

Effect of Tb substitution for Dy on superconductivity and magnetism inDy1−xTbxNi2B2Choi1, Kim2, Kim3 et al. 2005Phys. Rev. BSelf Cite8030View full textAdd to dashboardCite

“…Y substitution for Tb has also been studied in detail. 26,27 To understand the above-mentioned phenomena more clearly, we prepared Dy 1−x Tb x Ni 2 B 2 C ͑Dyu Tb͒ single crystals, in which T c was lower than T N . In that system, we found T c and T N behaviors that were strikingly different from those in the Dyu Ho system.…”