Origin of high transport spin polarization in La0.7Sr0.3MnO3:: Direct evidence for minority spin states -: art. no. 184433
Origin of high transport spin polarization in La0.7Sr0.3MnO3:: Direct evidence for minority spin states -: art. no. 184433
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DOI：
10.1103/physrevb.63.184433
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发表时间：
2001-05-01
影响因子：
3.7
通讯作者：
Mukovskii, Y
中科院分区：
文献类型：
--
作者：
Nadgorny, B;Mazin, II;Mukovskii, Y
利用点接触Andreev反射技术，我们对锰氧化物巨磁电阻材料的自旋极化进行了系统的研究。La0.7Sr0.3MnO3（LSMO）。令人惊讶的是，我们观察到一个显着增加的剩余电阻率的电流自旋极化。这种违反直觉的趋势可以理解为接触中从弹道传输到扩散传输的转变。我们的结果强烈地表明，LSMO确实有少数自旋态在费米能级。然而，由于它的电流自旋极化远高于态密度，这种材料可以在输运实验中模拟真正的半金属的行为。根据我们的结果，我们称这种材料为传输半金属。
Using the point-contact Andreev reflection technique, we have carried out a systematic study of the spin polarization in the colossal magnetoresistive manganite. La0.7Sr0.3MnO3 (LSMO). Surprisingly, we observed a significant increase in the current spin polarization with the residual resistivity. This counterintuitive trend can be understood as a transition from ballistic to diffusive transport in the contact. Our results strongly suggest that LSMO does have minority spin states at the Fermi Level. However, since its current spin polarization is much higher than that of the density of states, this material can mimic the behavior of a true half-metal in transport experiments. Based on our results we call this material a transport half-metal.