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arXiv 0808.3871cond-mat.supr-concond-mat.str-el
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用μ子自旋弛豫和磁化率研究Zn和Ni替代对La_(2-x)Sr_x_Cu_1-y_(Zn,Ni)_y_O_4_(x=0.15-0.20)中Cu自旋动力学和超导电性的影响

Effects of Zn and Ni substitution on the Cu-spin dynamics and superconductivity in La_2-x_Sr_x_Cu_1-y_(Zn,Ni)_y_O_4_ with x=0.15-0.20 studied by the muon spin relaxation and magnetic susceptibility

T. Adachi, N. Oki, Risdiana, S. Yairi, Y. Koike, I. Watanabe

摘要:

本文通过零场μ子自旋弛豫(ZF-μ SR)和磁化率(chi)测量,研究了Zn和Ni对La_(2-x)Sr_x_Cu_1-y_(Zn,Ni)_y_O_4_(x=0.15-0.20)的Cu自旋动力学和超导电性的影响。在最佳掺杂x=0.15的情况下,可以得出结论,磁性有序的形成需要比Zn更大量的Ni,这与我们之前x=0.13的结果相似。从超导(SC)和磁性区域的体积分数的估计,它已被发现为x=0.15的SC区域是在粗略的对应的区域,其中Cu自旋快速波动超出muSR频率窗口的Zn和Ni取代的样品。根据条纹模型,它遵循,即使x=0.15,自旋和空穴的动态条纹相关钉扎和本地化周围的Zn和Ni,导致静态条纹秩序的形成和超导性的抑制。这可能表明动力学条纹在空穴掺杂铜氧化物高T_c超导性出现中的重要性。另一方面,在x=0.18和0.20的过掺杂制度中,SC区域似乎与Cu自旋快速波动超出muSR频率窗口的区域大致对应,尽管似乎Cu自旋动力学和超导性受到SC和正常状态区域的相分离的影响。

英文摘要:

We have investigated effects of Zn and Ni on the Cu-spin dynamics and superconductivity from the zero-field muon-spin-relaxation (ZF-muSR) and magnetic-susceptibility, chi, measurements for La_2-x_Sr_x_Cu_1-y_(Zn,Ni)_y_O_4_ with x=0.15-0.20, changing y up to 0.10 in fine step. In the optimally doped x=0.15, it has been concluded that the formation of a magnetic order requires a larger amount of Ni than that of Zn, which is similar to our previous results of x=0.13. From the estimation of volume fractions of superconducting (SC) and magnetic regions, it has been found for x=0.15 that the SC region is in rough correspondence to the region where Cu spins fluctuate fast beyond the muSR frequency window for both Zn- and Ni-substituted samples. According to the stripe model, it follows that, even for x=0.15, the dynamical stripe correlations of spins and holes are pinned and localized around Zn and Ni, leading to the formation of the static stripe order and the suppression of superconductivity. These may indicate an importance of the dynamical stripe in the appearance of the high-T_c_ superconductivity in the hole-doped cuprates. In the overdoped regime of x=0.18 and 0.20, on the other hand, the SC region seems to be in rough correspondence to the region where Cu spins fluctuate fast beyond the muSR frequency window, though it appears that the Cu-spin dynamics and superconductivity are affected by the phase separation into SC and normal-state regions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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