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arXiv 1804.05321cond-mat.mtrl-sci
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$\mathrm{Co_2Fe_{1-x}Cr_xSi}$ Heusler合金:一种有前途的自旋电子学材料

$\mathrm{Co_2Fe_{1-x}Cr_xSi}$ Heusler Alloys : A promising material for spintronics application

Deepika Rani, Jiban Kangsabanik, K. G. Suresh, N. Patra, D. Bhattacharyya, S. N. Jha, Aftab Alam

摘要:

本文研究了Cr替代Fe对$\mathrm{Co_2FeSi}$合金的结构、磁性和输运性质的影响。使用X射线衍射(XRD)和扩展X射线吸收精细结构(EXAFS)光谱进行了全面的结构分析。四元Heusler化合物$\mathrm{Co_2Fe_{1-x}Cr_xSi}$与Cr含量(x = 0.1,0.3,0.5)被发现在立方结构结晶。基于同步辐射的EXAFS研究表明,反位无序随Cr浓度的增加而增加。发现所有合金的饱和磁化强度值均小于Slater Pauling规则所预期的值,这可能是由于一些固有的无序性。在5-300 K的温度范围内进行了详细的电阻率分析,考虑到不同的散射机制。残余电阻率比被发现随着Cr浓度的增加而减小。当x = 0.5时,由于弱的局域化效应,可以看到无序诱导的电阻率最小值。电阻率测量还表明,对于x = 0.1,半金属特性在高达100 K下仍然存在,而具有x= 0.3和0.5的合金即使在更高的温度下也显示出半金属性质的特征。使用更稳健的交换相关函数(即HSE-06)进行的第一性原理计算证实了整个浓度范围内的半金属量。理论模拟的带隙和磁矩恭维的实验结果,并在可能的情况下进行比较。所有这些性质使$\mathrm{Co_2Fe_{1-x}Cr_xSi}$成为一种有前途的自旋电子学材料。

英文摘要:

In this article, we investigated the effect of Cr substitution in place of Fe on the structural, magnetic and transport properties of $\mathrm{Co_2FeSi}$ alloy. A comprehensive structural analysis is done using X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Quaternary Heusler compounds $\mathrm{Co_2Fe_{1-x}Cr_xSi}$ with Cr content (x = 0.1, 0.3, 0.5) were found to crystallize in cubic structure. The synchrotron based EXAFS studies reveal that the anti-site disorder increases with the increase in Cr concentration. The saturation magnetization values in all the alloys are found to be less than those expected from the Slater-Pauling rule, which may be due to the some inherent disorder. A detailed resistivity analysis in the temperature range of 5-300 K is done, taking into account different scattering mechanisms. The residual resistivity ratio is found to decrease with increasing Cr concentration. A disorder induced resistivity minimum due to weak localization effect is seen for x = 0.5. The resistivity measurements also indicate that the half-metallic character survives upto 100 K for x = 0.1, whereas the alloys with x= 0.3 and 0.5 show signature of half- metallic nature even at higher temperatures. First principles calculation done with a more robust exchange correlation functional (namely HSE-06) confirms the half metallicity in the entire concentration range. Theoretically simulated band gap and magnetic moments compliment the experimental findings and are compared wherever possible. All these properties make $\mathrm{Co_2Fe_{1-x}Cr_xSi}$ a promising material for spintronics application.

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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