Co2Fe(Ti0.5Al0.5) epitaxial thin films: Structural and magnetic properties of a Heusler alloy with Z-site transition metal substitution
Co2Fe(Ti0.5Al0.5) epitaxial thin films: Structural and magnetic properties of a Heusler alloy with Z-site transition metal substitution
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Co2Fe(Ti0.5Al0.5) 外延薄膜：Z 位过渡金属取代的 Heusler 合金的结构和磁性
DOI：
10.1016/j.jmmm.2023.170946
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发表时间：
2023
影响因子：
2.7
通讯作者：
Comes, Ryan B.
中科院分区：
文献类型：
--
作者：
Budhathoki, Sujan;Rai, Anish;Law, Ka Ming;Nahar, Ridwan;Stewart, Andrew;Ranjit, Smriti;K.C., Shambhu;Isaacs-Smith, Tamara;Bikmukhametov, Ilias;Comes, Ryan B.
研究了在立方晶系MgO（001）、MgAl 2 O 4（001）和六方晶系Al 2 O3（112 × 0）衬底上用溅射束外延法生长的厚度为6 ~ 80 nm的Heusler Co2 Fe（Ti0.5Al0.5）（CFTA）合金薄膜的结构、静态和动态磁性能. X射线衍射测量表明CFTA薄膜的外延生长具有B2化学有序性，立方[001]和[220] CFTA轴分别垂直于立方和六方衬底。对MgO衬底上生长的薄膜的微观结构分析表明，薄膜的外延晶体取向均匀，且随应变畸变的变化较小，这解释了薄膜的X射线摇摆曲线值较大的原因，而在Al 2 O3（11 2 μ 0）衬底上生长的薄膜则表现为柱状生长，并伴有频繁的面内晶粒旋转.在立方衬底上生长的外延薄膜中观察到明显的四重磁晶各向异性。在Al 2 O3（11 2 × 10）衬底上生长的薄膜具有明显的单轴各向异性.饱和磁化强度为1.5。在室温下获得0 μ B/fu（其中fu表示分子式单位），与基于Slater-Pauling规则的预期值相比略小。铁磁共振谱发现一个有效的阻尼参数和不均匀的线宽加宽的母体化合物Co 2 FeAl中发现的那些，这表明，Ti取代可以实现没有负面影响的系统的磁性能。
We investigate the structural, static, and dynamic magnetic properties of epitaxial Heusler Co 2 Fe (Ti 0.5 Al 0.5)(CFTA) alloy thin films with thickness varying from 6 nm to 80 nm grown by sputter beam epitaxy on cubic MgO (001), MgAl 2 O 4 (001), and hexagonal Al 2 O 3 (11 2 ̄ 0) substrates. X-ray diffraction measurements indicate epitaxial growth of CFTA thin films with B2 chemical ordering, with cubic [001] and [220] CFTA axes normal to the cubic and hexagonal substrates, respectively. Microstructure analysis of films grown on MgO substrates reveals a uniformly oriented epitaxial crystal with small variations consistent with strain distortions, providing an explanation for the relatively large X-ray rocking curve values found. Meanwhile, films on Al 2 O 3 (11 2 ̄ 0) substrates reveal columnar growth with frequent in-plane grain rotations. A pronounced four-fold magnetocrystalline anisotropy is observed in epitaxial thin films grown on cubic substrates. A pronounced uniaxial anisotropy for films grown on Al 2 O 3 (11 2 ̄ 0) substrates is observed. A saturation magnetization of∼ 5. 0 μ B/fu (where fu represents formula unit) is obtained at room temperature, slightly smaller compared to the expected value based on the Slater-Pauling rule. Ferromagnetic resonance spectroscopy finds an effective damping parameter and inhomogeneous linewidth broadening comparable to those found in parent compound Co 2 FeAl, which suggests that Ti substitution can be achieved without negatively affecting the magnetic properties of the system.