The integration of ferromagnetic and ferroelectric materials into hybrid heterostructures yields multifunctional systems with improved or novel functionality. We here report on the structural, electronic and magnetic properties of the ferromagnetic double perovskite Sr2CrReO6, grown as epitaxial thin film onto ferroelectric BaTiO3. As a function of temperature, the crystal-structure of BaTiO3 undergoes phase transitions, which induce qualitative changes in the magnetic anisotropy of the ferromagnet. We observe abrupt changes in the coercive field of up to 1.2T along with resistance changes of up to 6.5%. These results are attributed to the high sensitivity of the double perovskites to mechanical deformation.
We report giant anisotropy in thermoelectric power factor ($S^2σ$) of marcasite structure-type PtSb$_{1.4}$Sn$_{0.6}$. PtSb$_{1.4}$Sn$_{0.6}$, synthesized using ambient pressure flux growth method upon mixing Sb and Sn on the same atomic site, is a new phase different from both PtSb$_2$ and PtSn$_2$ that crystallize in the cubic $Pa\bar{3}$ pyrite and $Fm\bar{3}m$ fluorite unit cell symmetry, respectively. Giant difference in $S^2σ$ for heat flow applied along different principal directions of the orthorhombic unit cell mostly stems from anisotropic Seebeck coefficients.
An integrated approach to doped thin films with strain tunable magnetic anisotropy: Powder synthesis, target preparation and pulsed laser deposition of Bi:YIG
Perpendicular magnetic anisotropy was found to be highly sensitive to the nominal thickness and morphology of laterally heterogeneous CoPd films in the vicinity of the metal insulator transition. We used the effect to tune the anisotropy by the width of lithographically patterned stripes with non-uniform cross-sectional thickness profiles. The phenomenon and the method can be suitable to control the local anisotropy of spintronic logic circuitry elements by their shape and lateral dimensions.
Cerium substituted yttrium iron garnet (Ce:YIG) epitaxial thin films are prepared on gadolinium gallium garnet (GGG) substrate with pulsed laser deposition (PLD). It is observed that the films grown on GGG(111) substrate exhibit perpendicular magnetic anisotropy (PMA) as compared to films grown on GGG(100) substrate. The developed PMA is confirmed from magneto-optical Kerr effect, bulk magnetization and ferromagnetic resonance measurements. Further, the magnetic bubble domains are observed in the films exhibiting PMA. The observations are explained in terms of the growth direction of Ce:YIG fi…
Broadband ferromagnetic resonance is measured in single crystalline Fe films of varying thickness sandwiched between MgO layers. An exhaustive magnetic characterization of the films (exchange constant, cubic, uniaxial and surface anisotropies) is enabled by the study of the uniform and the first perpendicular standing spin wave modes as a function of applied magnetic field and film thickness. Additional measurements of non-reciprocal spin wave propagation allow us to separate each of the two interface contributions to the total surface anisotropy. The results are consistent with the model of a…
Anisotropy and Morphology of Strained III-V Heteroepitaxial Films
III-V族半导体膜例如In $_x$ Ga $_{1-x}$ As/GaAs的应变相干异质外延具有用于电子和光电应用的潜力，例如高密度逻辑、量子计算架构、激光二极管和其它光电子器件。晶体对称性对这些膜的形态和它们的空间顺序有很大的影响。IV族应变异质结构的形成，例如沉积在Si上的Ge，通常使用基于Asaro-Tiller-Grinfeld不稳定性的分析模型来分析。然而，III-V族3D异质结构形成的控制动力学具有不同的对称性，并且更具各向异性。在表面能和扩散系数方面都出现了附加的各向异性。在这里，所产生的各向异性的管理动态研究的线性顺序。由此产生的可能的膜形态进行比较与实验观察到的在$_x$镓$_{1-x}$作为/GaAs薄膜。值得注意的是，它被发现，表面能各向异性起着至少一样重要的作用，表面扩散各向异性，如果不是更如此，在以前的假设相反。
External magnetic fields provide a macroscopic control mechanism to influence the microstructure of polycrystalline materials. We model the influence of strong magnetic fields on grain growth in thin films with a magnetic extended phase field crystal (XPFC) model. The magneto-structural effects are incorporated into the correlation function in reciprocal space. With this approach magnetic anisotropy, magnetostriction and mobility of grain boundary can be controlled and a variety of geometrical and topological properties consistent with experimental results can be determined.
Giant anisotropy of Gilbert damping in epitaxial CoFe films
金属铁磁薄膜的Gilbert阻尼是自旋电子学应用中的一个热点问题。本文报道了外延Co $_{50}$ Fe $_{50}$薄膜的巨吉尔伯特阻尼各向异性，其最大最小阻尼比为400%，这是由宽带自旋力矩和感应铁磁共振确定的.我们的结论是，这种阻尼各向异性的起源是不同的磁化取向的立方晶格中的自旋轨道耦合的变化，这是进一步证实了从各向异性的磁电阻的大小在Co $_{50}$ Fe $_{50}$。
We report measurements of magnon spin transport in a spinel ferrite, magnesium aluminum ferrite $\mathrm{MgAl_{0.5}Fe_{1.5}O_4}$ (MAFO), which has a substantial in-plane four-fold magnetic anisotropy. We observe spin diffusion lengths $> 0.8$ $\mathrm{μm}$ at room temperature in 6 nm films, with spin diffusion length 30% longer along the easy axes compared to the hard axes. The sign of this difference is opposite to the effects just of anisotropy in the magnetic energy for a uniform magnetic state. We suggest instead that accounting for anisotropy in exchange stiffness is necessary to explain …
