Epitaxial film growth and magnetic properties of Co2FeSi
Epitaxial film growth and magnetic properties of Co2FeSi
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DOI：
10.1103/physrevb.74.174426
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发表时间：
2006-11-01
影响因子：
3.7
通讯作者：
Adrian, H.
中科院分区：
文献类型：
--
作者：
Schneider, H.;Jakob, G.;Adrian, H.
我们用射频磁控溅射法生长了Heusler化合物Co_2FeSi薄膜。在（100）取向的MgO衬底上，我们发现了完全外延的（100）取向和L2（1）有序生长。在Al_2 O_3（11（2）over bar_0）衬底上，薄膜生长为（110）取向，并观察到多个面内外延畴。电阻率的温度依赖性在低温下表现出指数为7/2的幂律。对体磁性质的研究揭示了5.0 mu（B）/f. u的外推饱和磁化强度。在0 K。Al 2 O3上的薄膜表现出平面内的单轴各向异性，而外延薄膜在平面内是磁各向同性的。测量的X射线磁圆二色性的薄膜，使我们能够确定元素的特定磁矩。最后，我们已经测量了自旋极化在表面区域的自旋分辨近阈值光电发射，发现它强烈减少，与预期的体值的100%。磁化强度降低的可能原因进行了讨论。
We have grown thin films of the Heusler compound Co2FeSi by RF magnetron sputtering. On (100)-oriented MgO substrates we find fully epitaxial (100)-oriented and L2(1) ordered growth. On Al2O3(11 (2) over bar0) substrates, the film growth is (110)-oriented, and several in-plane epitaxial domains are observed. The temperature dependence of the electrical resistivity shows a power law with an exponent of 7/2 at low temperatures. Investigation of the bulk magnetic properties reveals an extrapolated saturation magnetization of 5.0 mu(B)/f.u. at 0 K. The films on Al2O3 show an in-plane uniaxial anisotropy, while the epitaxial films are magnetically isotropic in the plane. Measurements of the x-ray magnetic circular dichroism of the films allowed us to determine element specific magnetic moments. Finally we have measured the spin polarization at the surface region by spin-resolved near-threshold photoemission and found it strongly reduced in contrast to the expected bulk value of 100%. Possible reasons for the reduced magnetization are discussed.