Kharmouche A
LESIMS Laboratory, Department of Physics, Ferhat Abbas University of Setif, 19000, Algeria.
J Nanosci Nanotechnol. 2011 Jun;11(6):4757-64. doi: 10.1166/jnn.2011.4137.
Series of Co(x)Cr(1-x) thin films have been prepared by thermal evaporation onto Si(100) and Corning glass substrates, x ranging from 1 to 0.60, and the magnetic layer thickness from 17 to 220 nm. The dependence of the magnetic and crystallographic properties on the thickness of CoCr layers have been investigated. The chromium content effect on the saturation magnetization of the films has also been examined. Microscopic characterizations of the films, performed with X-ray diffraction (XRD) measurements, infer that all the samples are composed of hcp phase crystallites with good orientation of the c axis showing a (0001) preferred orientation. The grain size increases with thickness. Atomic force microscopy (AFM) observations show very smooth film surfaces, the highest rms value being 18 amgstroms. The saturation magnetization M(s) was found to decrease from 1400 emu/cm3 to a few emu/cm3 as x decreases from 1 to 0.60, for all values of the thickness. In-plane squareness up to S = 0.83 has been observed for the CoCr/Si thinnest film, and S = 0.90 for the Co/Si thinnest film, too. Magnetic Force Microscopy (MFM) study points out the absence of stripe domains equilibrium magnetization structure for the CoCr thin films whereas the thick Co films present a well defined stripe pattern. From the magnetocrystalline anisotropy field H(a) values extracted from the fit of the BLS spectra, we have computed effective magnetic anisotropy factors K(u), as well. Their negative values for the CoCr samples confirm an in-plane magnetic anisotropy for the thin film magnetization.
通过热蒸发法在硅（100）和康宁玻璃基板上制备了一系列Co(x)Cr(1 - x)薄膜，x的取值范围为1至0.60，磁性层厚度为17至220纳米。研究了CoCr层厚度对磁性和晶体学性质的影响。还考察了铬含量对薄膜饱和磁化强度的影响。通过X射线衍射（XRD）测量对薄膜进行微观表征，推断所有样品均由具有良好c轴取向的六方密堆积（hcp）相微晶组成，呈现出（0001）择优取向。晶粒尺寸随厚度增加。原子力显微镜（AFM）观察表明薄膜表面非常光滑，均方根（rms）值最高为18埃。对于所有厚度值，发现随着x从1减小到0.60，饱和磁化强度M(s)从1400emu/cm³降至几emu/cm³。对于CoCr/Si最薄薄膜，观察到面内矩形比高达S = 0.83，对于Co/Si最薄薄膜，面内矩形比也为S = 0.90。磁力显微镜（MFM）研究指出，CoCr薄膜不存在条纹畴平衡磁化结构，而厚Co薄膜呈现出明确的条纹图案。根据从BLS光谱拟合中提取的磁晶各向异性场H(a)值，我们还计算了有效磁各向异性因子K(u)。CoCr样品的负值证实了薄膜磁化存在面内磁各向异性。
