论文标题
Fe-3 $ d $杂质带状态的演变作为P型铁磁半导体（GA，FE）SB中高居里温度的起源
Evolution of the Fe-3$d$ impurity band state as the origin of high Curie temperature in p-type ferromagnetic semiconductor (Ga,Fe)Sb
论文作者
论文摘要
（ga $ _ {1-x} $，fe $ _x $）SB是Spintronic设备应用的有前途的铁磁半导体之一，因为当Fe浓度$ x $等于或更高时，它的curie温度（$ t _ {\ rm c} $）高于300 k。但是，（ga，fe）sb的高$ t _ {\ rm c} $的起源仍有待阐明。为了解决这个问题，我们使用谐振光发射光谱（RPE）和第一原理计算来研究Fe 3 $ d $ state的$ x $依赖性（ga $ _ {1-x} $，fe $ _x $）SB（$ x $ x $ x $ = 0.05、0.15、0.15、0.15和0.25）薄膜。观察到的Fe 2 $ p $ -3 $ d $ rpes光谱表明，越过费米水平的Fe-3 $ d $杂质乐队（IB）随着$ x $的增加而变得更加广泛，这在质量上与双交换互动的图片一致。获得的FE-3 $ D $局部密度与第一原理计算之间的比较表明，Fe-3 $ d $ IB源自少数派（$ \ downarrow $）$ e $州。结果表明，增加$ x $的$ e_ \ downarrow $电子之间的相互作用是高$ t _ {\ rm c} $ in（ga，ga，fe）sb的起源。
(Ga$_{1-x}$,Fe$_x$)Sb is one of the promising ferromagnetic semiconductors for spintronic device applications because its Curie temperature ($T_{\rm C}$) is above 300 K when the Fe concentration $x$ is equal to or higher than ~0.20. However, the origin of the high $T_{\rm C}$ in (Ga,Fe)Sb remains to be elucidated. To address this issue, we use resonant photoemission spectroscopy (RPES) and first-principles calculations to investigate the $x$ dependence of the Fe 3$d$ states in (Ga$_{1-x}$,Fe$_x$)Sb ($x$ = 0.05, 0.15, and 0.25) thin films. The observed Fe 2$p$-3$d$ RPES spectra reveal that the Fe-3$d$ impurity band (IB) crossing the Fermi level becomes broader with increasing $x$, which is qualitatively consistent with the picture of double-exchange interaction. Comparison between the obtained Fe-3$d$ partial density of states and the first-principles calculations suggests that the Fe-3$d$ IB originates from the minority-spin ($\downarrow$) $e$ states. The results indicate that enhancement of the interaction between $e_\downarrow$ electrons with increasing $x$ is the origin of the high $T_{\rm C}$ in (Ga,Fe)Sb.
