arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2103.10202cond-mat.str-elphysics.app-ph
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$4f$ - $3d$金属间化合物磁体的价涨落诱导的内禀矫顽力

Intrinsic coercivity induced by valence fluctuations in $4f$-$3d$ intermetallic magnets

H. Shishido, T. Ueno, K. Saito, M. Sawada, M. Matsumoto

摘要:

测量了Ce(Co $_{1-x}$ Cu $_{x}$)$_5$($0\le x \le 0.7$)(稀土永磁体中具有代表性的$4f$ - $3d$金属间化合物磁体)均匀化样品的磁化曲线的温度依赖性。观察到$x=0.3$和$x=0.4$的本征极化率显著增强,并持续到更高的温度。这一实验观察结果在理论上归因于$4f$ -电子之间的电子相关效应。也就是说,与传统的晶场效应相比,本征钉扎的发生源于由$4f$ -电子和$3d$ -电子之间强一个数量级的电荷转移过程贡献的有害增强的磁各向异性能量。结果表明,$4f$电荷转移过程取决于Ce的价态在CeCu $_5$与Ce $^{3+}$和CeCo $_5$与混合价态之间的交叉点的磁化方向.

英文摘要:

Temperature dependence of magnetization curves of well homogenized samples of Ce(Co$_{1-x}$Cu$_{x}$)$_5$ ($0\le x \le 0.7$), a family of representative $4f$-$3d$ intermetallic magnets found in rare-earth permanent magnets, is measured. A remarkable enhancement of intrinsic coercivity is observed with $x=0.3$ and $x=0.4$, persisting to higher temperatures. This experimental observation is theoretically attributed to an effect of electronic correlation among $4f$-electrons. That is, an intrinsic pinning happens originating in an anomalously enhanced magnetic anisotropy energy contributed by an order of magnitude stronger charge-transfer process between $4f$-electrons and $3d$-electrons, than the conventional crystal field effects. It is demonstrated that the $4f$-$3d$ charge-transfer process depends on the direction of magnetization in the middle of a crossover of the valence state of Ce between CeCu$_5$ with robust Ce$^{3+}$ and CeCo$_5$ with the mixed valence state.

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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