论文标题
Co $ _2 $ CRAL外延薄膜的结构，磁和运输特性
Structural, magnetic and transport properties of Co$_2$CrAl epitaxial thin films
论文作者
论文摘要
我们使用脉冲激光沉积技术报告了Co $ _2 $ $ _2 $ cral Heusler合金薄膜的物理性质。 $θ$ -2 $θ$模式的X射线衍射模式显示了单相B2型有序的立方结构的膜增长，存在（002）和（004）峰的存在，并且沿MGO（001）方向取向膜。 $ ϕ $〜沿（220）飞机扫描确认了四倍的对称性，并且被发现为CO $ _2 $ cral（001）[100] $ \ vert $$ \ vert $ \ vert $ mgo（001）[110] [110]。通过分析X射线反射率数据，提取了约12〜nm的厚度。等温磁化（M-H）曲线证实了在5和300〜K时具有明显滞后的薄膜的铁磁（FM）性质。从平面内M-H曲线中，饱和磁化值确定为2.1〜 $μ$$ _ {\ rm b} $/f.u.〜在5〜K和1.6〜 $ $ $ $ $ _ {\ rm B} $/f.u。在300〜K处，这表明膜中的软FM行为在5〜k时具有强制性范围$ \ $ 522〜OE。在500 〜OE磁场处的热磁化测量结果显示出低于100〜k的场冷却和零视野冷却曲线之间的分叉。归一化的场冷却磁化曲线遵循T $^2 $依赖关系，分析揭示了Curie温度在335 $ \ pm $ 11〜K左右。此外，低温电阻率表示与温度的半导体行为，我们发现电阻率的负温度系数（5.2 $ \ times $ 10 $^{ - 4} $ /k）。
We report the physical properties of Co$_2$CrAl Heusler alloy epitaxial thin films grown on single crystalline MgO(001) substrate using pulsed laser deposition technique. The x-ray diffraction pattern in $θ$-2$θ$ mode showed the film growth in single phase B2-type ordered cubic structure with the presence of (002) and (004) peaks, and the film oriented along the MgO(001) direction. The $ϕ$~scan along the (220) plane confirms the four-fold symmetry and the epitaxial growth relation found to be Co$_2$CrAl(001)[100]$\vert$$\vert$MgO(001)[110]. The thickness of about 12~nm is extracted through the analysis of x-ray reflectivity data. The isothermal magnetization (M--H) curves confirm the ferromagnetic (FM) nature of the thin film having significant hysteresis at 5 and 300~K. From the in-plane M--H curves, the saturation magnetization values are determined to be 2.1~$μ$$_{\rm B}$/f.u.~at 5~K and 1.6~$μ$$_{\rm B}$/f.u. at 300~K, which suggests the soft FM behavior in the film having the coercive field $\approx$ 522~Oe at 5~K. The thermo-magnetization measurements at 500~Oe magnetic field show the bifurcation between field-cooled and zero-field-cooled curves below about 100~K. The normalized field-cooled magnetization curve follows the T$^2$ dependency, and the analysis reveal the Curie temperature around 335$\pm$11~K. Moreover, the low-temperature resistivity indicates semiconducting behavior with the temperature, and we find a negative temperature coefficient of resistivity (5.2 $\times$ 10$^{-4}$ /K).
